ENGLEWOOD, Colo. -- The ligaments in Kyle Orton's left ankle are torn. He certainly isn't.

The quarterback adamantly wants to start Sunday against the San Diego Chargers and help the Denver Broncos snap out of a monthlong funk that has wiped out their 3½-game cushion in the AFC West.

Plus, how can Orton convince the Broncos' front office that he should be in their long-term plans if he's standing on the sideline sending in signals instead of running coach Josh McDaniels' offense?

Orton, in the final year of a contract that pays him a relatively paltry $1 million, has played through enough leg injuries to know it's not wise to rush back into action before he's healthy. He just wasn't the same quarterback in Chicago after spraining his other ankle midway through last season. His interceptions piled up, his passer ratings plummeted and he never rediscovered the touch that he had early in the season after he was carted off the field with a sprained ankle against the Detroit Lions on Nov. 2.

Eventually, the Bears soured on Orton and sent him and a bevy of draft picks to the Broncos for Jay Cutler.

Still, Orton's defiance was palpable Wednesday before he sat out practice.

"I came back last year as soon as I could, and I'll do the same thing this year," Orton said.

Orton acknowledged, however, that he rushed back into action last season after sitting out one game. He suffered through a 37-3 loss at Green Bay upon his hasty return, commencing a spiral that ended his tenure in Chicago.

"I wasn't even close for the Green Bay game," Orton admitted. "That's just how it is. I don't know if anybody is feeling 100 percent right now on our team. It's been a physical season, and I'm no different."

So Orton's mind-set is he's the starter unless and until McDaniels decides by week's end that Simms is.

"I'll come back as fast as I can and try to lead the football team and try to be in the huddle just like everybody else," Orton said. "In this sport, you've got to play when you are dinged up, and the quarterback is no different."

Besides, Orton said, this injury isn't anything like the one he had a year ago with the Bears.

"A different foot and a different deal. So it's different," he insisted. "It's not the same foot or the same type of thing. I played with leg injuries in the past. I hope I can do it this time.

"You know, last year was so tough because it was pushing off and that was my back leg, so that was tough. This will present a different challenge, I'm sure, but we'll see if I can play through it."

The Broncos, who are trying to avoid becoming just the third team in the Super Bowl era to miss the playoffs after winning its first six games, will either send out a quarterback with a puffy ankle to face an improved Chargers pass-rush or one who hasn't started a game since 2006.

Backup Chris Simms, a left-hander, unlike Orton, took the snaps with the starters at practice Wednesday.

Simms is the quarterback best known for having his spleen removed after taking a beating in a loss to the Carolina Panthers on Sept. 24, 2006, when he played for the Tampa Bay Buccaneers. He hasn't started a game since that day, although he did start the second half at Washington last Sunday after Orton was hurt on the Broncos' final play from scrimmage before halftime.

Simms was rusty, completing just three passes for 13 yards in 13 attempts in his first extended NFL action in three years.

"I'm sure that if you look at career statistics of guys coming in the middle of the game as the backup quarterback, I'm sure they're not through the roof," Simms said.

Some snaps with the first-team offense will get his rhythm back, suggested Simms, who has started 16 games in six seasons.

"A few reps will definitely help things out," he said.

Against the Redskins, Simms either fired passes over the heads of flustered wide receivers Brandon Marshall, Eddie Royal and Jabar Gaffney or bounced balls at their feet.

"I think the biggest thing is getting my eyes right and really just getting timing and rhythm down with the guys," Simms said. "I will get as greased up as I can, and if Kyle is ready to go, then it will be all for naught."

Marshall also missed practice Wednesday. The Broncos said the wide receiver had a neck injury.