Kaepernick likely to start season on bench after weak performance

Colin Kaepernick played in a football game for the first time in 292 days Friday night.

And he looked like a quarterback playing for the first time in 292 days.

Kaepernick’s attempts to shake off nine-plus months of rust were overwhelmingly unsuccessful in the 49ers’ 21-10 preseason loss to the Packers at Levi’s Stadium. He completed 2 of 6 passes for 14 yards in three possessions, which netted one first down and three punts. His last three passes, all incompletions, were either batted down or tipped by Green Bay defenders.

On a night when the 49ers managed 11 first downs and 195 yards, head coach Chip Kelly offered that Kaepernick was “up and down, I think, like all of us offensively.”

The obvious conclusion: Blaine Gabbert will start the regular-season opener against the Rams on Sept. 12.

For his part, Kelly said he wasn’t ready to announce a starter: “We’ll sit down as a staff and kind of see where we are,” he said.

Wide receiver Trevor Davis (11) of the Green Bay Packers attempts to make a catch in the end zone as he is being defended by cornerback Jimmy Ward (25) of the San Francisco 49ers during the second quarter of their NFL preseason game at Levi's Stadium in Santa Clara, Calif. on Friday, Aug. 26, 2016. less Wide receiver Trevor Davis (11) of the Green Bay Packers attempts to make a catch in the end zone as he is being defended by cornerback Jimmy Ward (25) of the San Francisco 49ers during the second quarter of ... more Photo: Stephen Lam, Special To The Chronicle Photo: Stephen Lam, Special To The Chronicle Image 1 of / 12 Caption Close Kaepernick likely to start season on bench after weak performance 1 / 12 Back to Gallery

Gabbert earning the job, of course, was the likely outcome before kickoff, unless Kaepernick could summon his early career magic in his preseason debut. Instead, the evening provided a bit more pain for Kaepernick, who missed all but three offseason practices after undergoing three surgeries and was sidelined for the first two exhibition games with a shoulder injury.

Still, Kaepernick provided a relatively positive assessment of his 2016 debut.

“I don’t think there was rust,” Kaepernick said. “It just felt good being back on the field. Just excited to be out there — wish we would have done a little bit more. But it was good to get out there and get my feet wet...

“I think overall I felt confident in my reads. I felt confident in what the offense was doing. We just have to be more productive on first and second down to stay out of those third and longs.”

The 49ers will play their preseason finale Thursday in San Diego, a game in which the majority of starters typically don’t play. However, Kaepernick still believes he could win the Week 1 starting assignment.

“I think so,” Kaepernick said. “That’s really up to Chip and the coaching staff, but in my mind I can go out and win it.”

Before Kaepernick was shelved this summer, Kelly said he wanted both quarterbacks to have snaps with the first-team offense in the preseason so they could be evaluated fairly. And Kelly followed through Friday. He started Gabbert and explained that decision by saying he was just concerned about both players getting snaps with the first team. Kaepernick was asked whether he wanted to start Friday.

“That’s not something that’s up to me,” he said. “I just go out and do the best with the position I’m put in. So I want to make sure I give my all to this team and put my best foot forward.”

Gabbert played the first two series and completed 2 of 3 passes for 14 yards. On his first drive, he overthrew a deep pass to wide receiver Quinton Patton, who had beaten cornerback Sam Shields and was all alone for a potential 75-yard touchdown.

Gabbert’s completions, both to tight end Garrett Celek, came on his second drive, a five-play, 53-yard touchdown march that was capped by a 3-yard lateral to Patton. The drive was highlighted by a 27-yard scamper by running back Carlos Hyde, whose longest carry in his injury-marred 2015 season went for 22 yards. Hyde left the game with a concussion later in the first half.

On the 49ers’ next drive, which began with 14:51 left in the second quarter, Kaepernick was cheered as he jogged onto the field with most of the first-team offense in his first game at Levi’s Stadium since Nov. 8.

However, the applause quickly disappeared.

On his first play, Kaepernick was forced out of the pocket and completed a high-risk 2-yard pass to tight end Vance McDonald. Two plays later, he completed a 12-yard pass to well-covered wideout DeAndrew White, who leapt for the first-down catch.

And that was it for Kaepernick highlights. On his final nine plays, Kaepernick went 0-for-4 and the 49ers netted 19 yards.

It was the type of unsightly stretch that sent Kaepernick to the bench after eight starts last year.

On Friday, it ensured he’ll begin the 2016 season in the same place, although Kelly suggested his spot on the team is safe when asked about Kaepernick’s job security.

“There's never been a conversation about cutting Colin Kaepernick,” Kelly said.

Eric Branch is a San Francisco Chronicle staff writer. Email: ebranch@sfchronicle.com Twitter: @Eric_Branch

3 notables

CB Chris Davis: After a strong summer, Davis had trouble keeping up with shifty WR Randall Cobb, who beat him on a 6-yard TD catch. Davis also fell down on a 15-yard pass to Cobb.

OLB Tank Carradine: The position switch is going well for the 2013 second-round pick, a disappointment at defensive tackle. Carradine had a sack and routinely generated pressure.

OLB Marcus Rush: After spending 2015 on the practice squad, the undrafted free agent picked up another sack, a takedown that came on the heels of his three-sack performance last week.