Bill Belichick kicked Wednesday off by talking about the need for the team to grind through training camp as the first week comes to a close. A couple of hours later he gathered his team to discuss that very topic after practice in hot and humid conditions in Foxborough.

The attrition that is normally seen at this stage began to rear its head on Wednesday. Despite making it through the first several practices with remarkably few players missing, the absences are starting to pile up. In addition to those missing, several players are clearly dealing with and fighting through various physical limitations as the work continues.

"It's just part of playing football," safety Jordan Richards said after practice. "You have to keep fighting and you have to be able to maintain your focus. We're all trying to deal with that stuff out here and we just have to keep working hard and keep fighting through it."

The wide receiver position in particular is being tested. Rookie Cody Hollister went down with an apparent shoulder injury July 28 and hasn't practiced since. Malcolm Mitchell has been in uniform but hasn't practice since opening day, instead working on the lower field with other rehabbing players. The same is true of Danny Amendola, although he has taken part in the last two sessions toward the end working as a punt returner. As a result, Tony Washington and K.J. Maye were signed to bolster the depth.

That was tested further on Wednesday when there were some additions to the list. Julian Edelman was limping around and spent some time with trainers before returning to action. Chris Hogan appeared to injure his right knee and also was tended to. Matthew Slater, who has worked a lot as a receiver the last few days, injured his leg and left practice about midway through. Slater initially tried to remain at practice before making his way to the medical tent. Shortly thereafter he walked gingerly down the back hill and made his way to the locker room.

Edelman was seen hobbling throughout the remainder of the work but made it through. Hogan put a sleeve on his right knee but wasn't able to finish practice. Instead he worked on a stationary bike and had a wrap around his keen by the end of practice. He did remain on the field and spent time with his family after practice.

"Today was a grind. [It's] super humid out. It's getting through the dog days because we just have to keep on pushing through camp," Rob Gronkowski said. "I think it's our fourth full pad [practice]. We've got a good week coming up, a good practice today. We just have to improve, keep doing our routine and keep doing better."

The conditions seemed to impact practice as once again the Patriots were not at their finest. Here are one man's observations from the team's sixth practice and fourth in full pads.

-Linebacker Dont'a Hightower and defensive tackle Alan Branch remained on PUP while rookie offensive lineman Andrew Jelks is still on NFI. They joined Mitchell and Amendola working on the lower field. There were some additions to the rehab group as well, most notably running back Mike Gillislee. Gillislee said he tweaked his hamstring and that limited him during the spring. It is unknown if this was the reason for his absence on Wednesday. Safety Duron Harmon was back in uniform but also limited to rehab while rookie safety David Jones continued working his way back from a leg injury. Tight end James O'Shaughnessy, who left Tuesday's practice early, was in uniform but stayed with the rehab group. Finally, rookie defensive tackle Josh Augusta missed practice and was not seen on the fields.

-"The Boys of Fall" once again led things off during the stretching period. It's the fifth straight day the Kenny Chesney classic was the first song played.

-Despite only being officially retired for three days, Rob Ninkovich was on the field throughout practice and served in an advisory role. He spent a lot of time with rookies Deatrich Wise and Derek Rivers, offering instructions to the two edge players at various times. Ninkovich expressed a desire to possibly get into coaching at some point but it was strange to see him on the field so quickly after Sunday's press conference.

-Dion Lewis got some extra stretching in between the practice fields early on. A member of the training staff spent several minutes with him before the running back returned for his positional drills. He looked none the worse for wear once practice kicked off as he was darting around in his normal fashion, showing no signs of any potential injury.

-The entire defense pushed the six-man blocking sled downfield at the start of practice. It was funny to watch at times as there were reps that clearly had some smaller defensive backs on one side with bulk defensive linemen on the other, which made for some uneven movement. The sled made it past the end zone nonetheless.

-Geneo Grissom had to run a penalty lap after jumping offside in a one-on-one pass rush drill.

-There was a lot of emphasis on the running game during practice, particularly early on when there were some half-line drills near the goal line. Rex Burkhead took a lot of reps with Gillislee out. Gronkowski made an excellent block to seal the edge on one rep, giving a nice lane for the back to run through.

-One of the first one-on-one reps between the wide receivers and defensive backs featured Edelman and Stephon Gilmore, the participants in Tuesday's fight that sent both to the showers. Edelman ran a long-developing route that featured several cuts and changes of direction. Gilmore did a good job of sticking with him but Jacoby Brissett was able to hit Edelman anyway. It's not the first time the route has been featured during camp but it's hard to imagine any pass protection offering enough time for such a play to develop in game conditions.

-During the same drill Hogan made a nice back shoulder catch with Justin Coleman tight in coverage. It was on this play that the wideout appeared to bang up his knee.

-The offense wasn't overly crisp at any point during practice but that may have been due at least in part to the work of the secondary. Malcolm Butler, Gilmore, Coleman and Jonathan Jones were extremely competitive on Wednesday (really throughout camp) and that group made life difficult on the offense. Jones continues to get plenty of reps as the third corner and on Wednesday Eric Rowe didn't take many at all. Jones made a terrific interception off Tom Brady in the end zone while covering Edelman, leaping with one hand to deflect the pass to himself as he fell to the turf. Belichick often likes to find roles for his younger players and it's clear that Jones is getting a chance to earn defensive snaps in addition to the special teams role he carved for himself last year as a rookie.

-During the first team period of 11-on-11s, the offensive line featured some wrinkles. After starting with the normal cast of characters, Ted Karras replaced Shaq Mason at right guard on the second play while Cam Fleming entered at left tackle with Nate Solder moving to the extra tight end sot. Solder then sat out the next play – as he would in game conditions after serving as an eligible receiver – while Karras moved to center for David Andrews and Mason returned. On the following play, Karras replaced Joe Thuney at left guard while Andrews returned.

-Defensively, Wise and fellow rookie Harvey Langi continue to see time with front line players. Wise got plenty of reps at left defensive end opposite Trey Flowers, a spot Grissom manned earlier in camp. He also got a lot of reps as an interior rusher in sub sets. Langi joined Kyle Van Noy and Shea McClellin at linebacker with Van Noy working in the middle. Langi spent most his time rushing the passer with varying levels of success.

-Rookie defensive tackle Adam Butler also continues to get some run early in camp. He worked as part of the sub defense as an interior rusher on a number of occasions. There were also some sub looks where Flowers worked as a standup rusher from the inside while Wise took his spot at right defensive end.

-During that segment, coaching assistant Brian Belichick was seen signaling calls into the back end of the defense.

-When Joe Cardona missed the first two practices of camp and Ninkovich was nowhere to be found, there was a question as to who might fill in as long snapper. While the Patriots chose not to do any kicking on those days, we may have gotten our answer on Wednesday. James Develin took a couple of reps during a punting period, sending a pair of accurate snaps back to Ryan Allen. Develin later said he was the backup to Giants long snapper Zak DeOssie while in college at Brown.

-Tight end Dwayne Allen is another player who appears to be fighting through some discomfort. He hasn't missed any time but often receives extra stretching and attention from the training staff. That was the case on Wednesday again, but he didn't miss any reps.

-There weren't many reps for Jimmy Garoppolo at practice on Wednesday. Tom Brady assumed a heavy workload while Garoppolo and Brissett filled in. Garoppolo again appeared to struggle with his accuracy as well as his timing. He did make a nice connection with Edelman on a backside crossing route that caught the secondary out of position. But otherwise it was another quiet day for Garoppolo. The final team period featured Brady working with the first group on the right field while Brissett ran the show on the left field with Garoppolo watching. When Brissett was done, he ran over and watched Brady finish up while Garoppolo took the final couple of reps. He missed a wide open Austin Carr in the end zone when his throw was low and behind the rookie.

-Stephen Gostkowski didn't kick any field goals, which is a good thing considering the kicker was wearing a pair of Nike sneakers instead of his cleats. Not sure I've ever seen that before Wednesday.

-Brady and Gronkowski spent some time chatting with Josh McDaniels on the opposite field during the final special teams period. It brought back memories of the work they've done in the past with Darrelle Revis off to the side.

-Richards for some reps alongside Patrick Chung while Devin McCourty was on the sideline. Richards is generally considered a more physical safety in Chung's mold but the two worked together at times during practice.

-Andrews was the final player to show signs of discomfort. On the final rep of the day he was slow to get back to his feet but eventually made it without seeking any additional medical attention.

-There was some plus-50 punting for Allen to close out practice and there were signs of the Patriots attention to detail during the drill. One kick saw D.J. Foster leap to keep the ball out of the end zone. Edelman was back to receive the punt and was close by as it landed at the 1. Since Foster had touched the ball it was great awareness by Edelman because the ball remains live and there's no danger of a fumble since it was already illegally touched by the punting team. So, Edelman can return it without fear of a turnover.

-Several players took some time to chat with the media after practice. That group included Gronkowski, Richards, Thuney, Develin, Burkhead, Karras, McCourty, Langi, Kony Ealy, James White and Hogan. White and Hogan conducted their interview together with former Patriots fullback Heath Evans of NFL Network.

-The Patriots will be back at it on Thursday with practice scheduled to begin at 9:15 a.m. The workout is once again open to the public. As always, please check with Patriots.com for all the latest schedule changes during training camp.