FOXBOROUGH, Mass. -- San Diego Chargers quarterback Philip Rivers returned to the practice field Friday and remained "optimistic" his sprained right knee would heal enough for him to play in the AFC championship game against the New England Patriots.
Chargers coach Norv Turner took a more cautious approach. He listed Rivers as doubtful and said it would be a gametime decision Sunday.
"We want him to be able to move well enough to protect himself," Turner said.
Rivers took about one-third of the snaps in practice. He was hurt last weekend in the 28-24 playoff victory over the defending Super Bowl champion Indianapolis Colts, and backup Billy Volek led the winning touchdown drive.
"The way I felt Monday morning, I didn't think I'd feel as good as I do right now," Rivers said. "Certainly, it can ease my mind a bit."
Under NFL rules for reporting injuries, someone listed as doubtful has a 25 percent chance of playing that week. Until Friday, teams were required to merely list whether a player practiced or not -- Rivers did not work out Wednesday or Thursday.
Defensive tackle Jamal Williams missed practice for the third consecutive day Friday, and his status for Sunday's AFC title game is questionable. Outside linebacker Shawne Merriman continues to be limited due to an illness, but is listed as probable in Friday's injury report.
Patriots coach Bill Belichick said San Diego's injury problems were of little concern to him.
"We get ready for all 53 players every week," he said. "We don't have any control over that."
Copyright 2007 by The Associated Press