ORCHARD PARK, N.Y. (June 11, 2007) -- The Buffalo Bills are prepared to move on without Darwin Walker after they couldn't agree on a new contract with the veteran defensive tackle before the start of a mandatory minicamp.

Talks continue, but general manager Marv Levy said the ultimate decision to report to the team rests with Walker, who is under contract, and has been advised he's subject to being fined.

"We'd like to have him," Levy said. "But if he's not going to be here, we'll go on without him. That's all it amounts to."

Walker is holding out while seeking an extension to the two years he has remaining on his contract. Negotiating a new deal was a condition the seven-year NFL veteran placed on the Bills in March after the team acquired him in a trade that sent linebacker Takeo Spikes to Philadelphia.

Walker has not yet reported to the Bills and has already missed the team's 12 voluntary workouts. Under NFL rules, players are subject to fines only when they miss a mandatory session, such as this week's three-day camp.

Citing team policy, Levy would not say if Walker has been fined.

Walker's agent, Albert Irby, remained hopeful, but was disappointed a deal still hasn't been reached.

"We asked for this trade," Irby said. "(Walker) definitely wanted to be there. The fact that he's not there yet is very disappointing."

Irby said talks were still progressing slowly, even though the two sides stepped up negotiations over the past week.

Levy said the team does not regret making the trade, knowing the conditions the player set: "No, not yet," Levy said.

And he remains hopeful a deal still can be reached.

The Bills can return Walker to Philadelphia if he doesn't report by Aug. 5. Buffalo would receive a sixth-round pick in next year's draft as compensation.

That would be a setback after the Bills acquired Walker to bolster the defensive line. A penetrating tackle who can pressure the quarterback, Walker was considered a good fit in the Bills' defensive scheme.

He had eight sacks in 17 games, including playoffs, last season, and has 26 1/2 sacks over the past five years, fourth best among defensive tackles during that span.

Defensive end Aaron Schobel understood Walker's absence.

"Bottom line is, it's business," Schobel said. "For him, he's got to look after his family and himself. That's how this league is set up."

Walker was the lone player not attending practice June 11.

Running back Anthony Thomas (leg injury), defensive tackle John McCargo (foot) and tight end Robert Royal (shoulder) were held out of team drills.