SAN DIEGO -- Chargers receiver Chris Chambers described his availability for Sunday's game against New England as "day to day" after missing Wednesday's practice with a sprained left ankle.

Chambers could be in danger of missing the game and said he didn't wish to talk about the level of pain he was feeling four days before kickoff.

"I can't really describe it, and it's not something I want to discuss anyway," Chambers said. "So I have no comment on any of that stuff. It's day to day right now. Hopefully, it will gradually get better."

Chambers injured the ankle on the final play of the third quarter during Sunday's loss to Miami. He said it was "frustrating" not to be able to finish the game against his former team.

He also was taken aback by what he heard from Dolphins fans upon catching his first pass in Sunday's game: a lot more boos than cheers.

"It surprised me a little bit," Chambers said. "I talked to a couple guys on their team, and they couldn't believe it themselves because I'm received very well in that area. It's just part of the game.

"It actually got me fired up. I couldn't wait to make a play at some point of the game and be able to contribute that way. But it was fine."

Chambers scored a touchdown in the third quarter. He said Wednesday that he had planned to do something for the crowd if he scored -- "blow a kiss, or some nice gesture," Chambers said -- but changed his mind after the booing.

Cassel's journey

You think the Chargers have struggled to replace Shawne Merriman? How about trying to replace Tom Brady.

Matt Cassel, about as nondescript a backup quarterback in the NFL just five weeks ago, was suddenly thrust into that predicament when New England lost Brady to a season-ending knee injury in Week 1.

Even Patriots coach Bill Belichick admits that drafting Cassel in the seventh round in 2005 was a reach. Cassel didn't even start a single college game at USC, where he played behind Heisman Trophy winners Carson Palmer and Matt Leinart.

"It was the seventh round," Belichick said. "So at that point in the draft, that's the time where you take a shot at guys who have something going for them, but if they were proven commodities, they wouldn't be sitting there in the seventh round. So that's why we did it."

Cassel arrived in training camp and found four other quarterbacks waiting: Brady, and veterans Doug Flutie, Chris Redman and Rohan Davey.

"I had to work my way up through it and earn my spot then and I take that approach each and every year," Cassel said. "You have to earn it in this league. Nothing's given to you."

Cassel has completed 67.3 percent of his passes for 707 yards. He has thrown three touchdown passes and three interceptions.

Tomlinson out

LaDainian Tomlinson missed practice Wednesday because of his lingering right big toe injury. He said he hopes to participate in at least part of Thursday's practice.

He said the level of soreness now isn't as bad as the pain he dealt with a month ago.

"I think I'm close to getting back to where I want to be," Tomlinson said. "I definitely want to take as much time and as much pressure off it as possible. Obviously, as you well know, the more you play on it, it's never going to get completely healthy."

Et cetera

C Nick Hardwick isn't a big fan of Patriots DE Richard Seymour because of what he considered dirty play in last season's AFC Championship Game. But Hardwick won't be discussing Seymour this week. "I'm not really answering those questions," Hardwick said. … OLB Jyles Tucker missed practice, and his hamstring injury could sideline him through October. FB Mike Tolbert (ankle) was a limited practice participant. … The Chargers announced that "enough tickets" have been sold to lift the television blackout for Sunday's game. Kickoff is at 5:15 p.m. on NBC.