Alex Smith

Alex Smith is baffled by the fact that he lost the starting job as 49ers quarterback to Colin Kaepernick.

Smith, who was NFC Offensive Player of the Week just one month ago, is medically cleared after suffering a concussion Nov. 11 against the Rams, but he won’t be playing for the second Sunday in a row when the 49ers and Rams square off.

Coach Jim Harbaugh has again named Kaepernick the starter this week.

“I feel like the only thing I did to lose my job was get a concussion,” Smith said.

Smith ranks fifth in the NFL with a passer rating of 104.1 and leads the league with a 70.0 completion percentage.

“You kind of state your case with your play and I felt like I’ve done that,” Smith said. “It’s tough. It stings the most just because I really felt there was something special going on here and you sacrifice and invest so much time. I felt like I was playing good football. I have no idea what’s going to happen from here. All I can do now is just prepare and get ready.”

Since replacing Smith, Kaepernick has completed 48-of-74 passes for 680 yards and three touchdowns with one interception, and he’s been sacked six times. He led the 49ers past the Saints and Bears.

Harbaugh says he’ll keep his mind open going forward about whether to use Kaepernick or Smith.

“Alex is a class act all the way,” Harbaugh said. “He’ll prepare as if he is the starter. And that’s what we would expect. And be ready to go in and play and contribute to this football team. We’ve got two quarterbacks that we feel great about as the starting quarterback. Anything’s a possibility. I would assume nothing or rule out anything.”

Alex Smith

Quarterback Alex Smith will not start for the 49ers on Monday night against the Bears because he was not given clearance from a neurologist after suffering a concussion last week, according to an ESPN report.

If the report proves true, Colin Kaepernick will make his first start in Smith’s place.

Smith had been practicing last week and reports indicated he was on track to start the game.

The Monday night matchup is a backup showdown, as the Bears already ruled out starting quarterback Jay Cutler last week. Jason Campbell will start in his place.

Jay Cutler

When the Bears and 49ers play Monday night, it might be a matchup of backup quarterbacks as both Bears QB Jay Cutler and 49ers QB Alex Smith deal with post-concussion issues from hits received in their last game.

Cutler missed practice on Thursday and his status remains in question for Monday night’s game. Smith practiced Thursday and looks more likely to start, ESPN’s Ed Werder tweeted.

Jason Campbell would replace Cutler if it turns out he is not ready. Colin Kaepernick would start in place of Smith.

Bears coach Lovie Smith said Cutler continues to improve, but it’s not clear if he’ll be ready to go against the 49ers. Smith added that Cutler could play even if he doesn’t practice.

Meanwhile, the NFL has fined Texans linebacker Tim Dobbins $30,000 for his helmet-to-helmet hit on Cutler during the first half of Sunday night’s game.