SANTA CLARA, Calif. — It took 344 days for Colin Kaepernick to reclaim the San Francisco 49ers’ starting quarterback job.

Stripped of that title last Nov. 2, Kaepernick was announced Tuesday as the starter for the free-falling 49ers (1-4) in Sunday’s visit to the Buffalo Bills (3-2).

“He said, ‘Let’s go,’” coach Chip Kelly said of Kaepernick’s reaction.

Blaine Gabbert was 4-9 as starter since then-coach Jim Tomsula promoted him ahead of Kaepernick at midseason last year. Gabbert’s 69.6 passer rating is second worst in the league this season, ahead of only the New York Jets’ Ryan Fitzpatrick (64.8).

“It’s not Blaine’s fault,” Kelly said. “It’s just as a group offensively we need to be better in a lot of ways. So we want to see what we can do and make a move here.

“It’s really one of the only maneuvers we can do based on our depth.”

Kelly had no updates regarding a possibly revised contract for Kaepernick.

“I don’t deal with contracts. It’s got nothing to do with his contract,” Kelly said. “It’s a football decision. I don’t even know where his contract is at. That’s a good question for him.”

The 49ers reportedly have presented Kaepernick a revised contract that would eliminate his injury guarantee toward next year’s $14.5 million salary. That deal, which could make him a free agent next spring, has not been finalized. Kaepernick confirmed that there have been discussions with the team, but he said he feels “no pressure” to get the deal done before Sunday’s game.

Kaepernick has played only three snaps this season: three handoffs at the end of a 28-0, season-opening win over the Los Angeles Rams.

“I’m ready to play,” Kaepernick said Tuesday. “It’s been about a year since live-game action. So I’m itching to get back out there.”

Kaepernick said looking at the offense, “there’s just small things here and there that we need to clean up, we need to correct, as a whole.”

“Hopefully those are things that we progress on this week and show Sunday,” he said.

Kaepernick started 47 consecutive regular-season games — plus a 4-2 playoff record — before getting benched. Rehabilitation from multiple surgeries (left shoulder, left knee, right thumb) limited his participation throughout the offseason program, and a sore shoulder shelved him nearly two weeks during training camp.

“He’s not the same guy he was in 2013, if you look at him physically,” Kelly said, referring to Kaepernick’s body change after the surgeries last November. “I’ve said since day one, he’s worked extremely hard since his rehab.

“He physically is not where he was pre-injury,” Kelly added. “Before that, he was a little bit bigger, a little bit faster, a little bit stronger. He will admit that. He’s worked as hard as anybody I’ve been around in terms of his rehab.”

Gabbert will be the No. 2 quarterback Sunday when the 49ers look for their first road win in three outings.

“They were fine,” Kelly said of telling the quarterbacks. “They’re both professionals. They both understand. Obviously the conversation with Kap is different than it was with Blaine. It is what is and we’ve got to make those decisions.”

Kelly said Kaepernick has had no recurrence of shoulder or arm discomfort since that shelved him for nearly two weeks during training camp. Now, he is physically and mentally ready to reprise his starting role.

“I have the same expectation for our team: to be successful and score points on the offensive side of the ball,” Kelly said. “They’re both the similar-type athletes. They both run. They both throw. Schematically we’re not going to change our entire offense to do this. You’re not dealing with two different athletic people.

“Blaine had 70 yards rushing our last game on 10 attempts. Blaine can run and do what we’re doing offensively. Kap can do what we’re doing.”