Rivers and Gates now listed as Doubtful

Sources told The San Diego Union-Tribune today the quarterback also has a partially torn anterior cruciate ligament in his right knee in addition to the sprained medial collateral ligament the team has made known.

“It'll be day-to-day,” General Manager A.J. Smith said. “We're going down the same road as (Antonio) Gates.” Gates played Sunday at Indianapolis after a pre-game workout to test his dislocated big toe, but was largely ineffective. He also has been listed as doubtful for this Sunday's game.

Rivers was on the practice field this morning for the first time this week, wearing a brace on his right knee. There was no brace on his left knee, on which he has played the past 5½ games with a sprained MCL. During the portion of practice open to the media, he threw passes with the first team.

“It always falls on the player,” Smith said. “The doctors and medical people do so much. The coach and general manager are on the outside. The ultimate decisions is the player's – unless he physically can't go or it will do harm for your future.”

Smith, as he always does, declined to discuss the specific injury. But he said, “We would never jeopardize any player.”

A sports medicine expert said yesterday it was possible for Rivers to play with a partial tear of his ACL.

“When you get into the category of partial tears, no one really knows,” said Dr. James Gladstone, an orthopedic surgeon and chief of sports medicine at Mt. Sinai School of Medicine. “There have been studies out there that suggest if (the ACL) is 50 percent intact, you may be OK. The only way of knowing is you play.”

Even if Rivers does play, the fact his knee is further damaged could affect how long he plays or how much trauma he can handle during the game.

It will also affect how he moves.

The ACL, which along with the PCL forms a cross at the center of the knee, works to stabilize the knee. Its health affects quick starting and stopping and change of direction.

What is not known is the severity of Rivers' tear in either his MCL or ACL. Sprains are classified in three degrees – as a stretching (first degree), partial tear (second degree) and total tear (third degree).