Kansas City Chiefs quarterback Brady Quinn is being evaluated for a possible concussion and his status for Thursday night’s game at San Diego won’t be known until later in the week.

Coach Romeo Crennel said Monday that Quinn will start against the Chargers if he’s cleared to play. Otherwise, Matt Cassel will be back under center for the Chiefs.

“Just depends on what the doctor tells me,” Crennel said. “If the doctor tells me he can go, he can go. If the doctor tells me he can’t go, he can’t go.”

Quinn was hurt in the first quarter of Sunday’s 26-16 loss to the Oakland Raiders, though it’s unclear when the injury occurred. He was sacked by Rolando McClain and then took another shot while floating a pass that was intercepted.

He left the field and went down the tunnel leading to the locker rooms, and Crennel said a trainer told him at that point that Quinn had sustained a “head injury” and was unavailable.

Crennel said that the former Browns quarterback wasn’t at the practice facility Monday while he underwent tests.

Smith leads 49ers to win

On an almost perfect Monday night for Alex Smith, the San Francisco 49ers flexed their NFC West dominance with a 24-3 flattening of the host Arizona Cardinals.

Smith completed 18-of-19 passes for 232 yards and three touchdowns two to Michael Crabtree and one to Randy Moss, as San Francisco (6-2) opened a two-game lead in the division and sent Arizona (4-4) to its fourth loss in a row.

Pagano visits Colts

Indianapolis Colts head coach Chuck Pagano made it back to the team complex for a staff meeting Monday.

It’s the first time Pagano has been back since being diagnosed with a form of leukemia Sept. 26 Pagano, whose white blood-cell count has increased as he has undergone treatment for the illness, is scheduled to start a second round of chemotherapy next week.

Around the league

Joe Mays is out for the season after suffering a serious injury to his lower left leg in the Denver Broncos’ win over the Saints. … The Indianapolis Colts waived running back Mewelde Moore and nose tackle Antonio Dixon and promoted cornerback Marshay Green and fullback Robert Hughes from the practice squad to the active roster.

Trade deadline moved

The NFL moved its trade deadline back two days to Thursday because of potential complications from Hurricane Sandy.