SANTA CLARA, Calif. (AP) — With the San Francisco 49ers mired in a four-game losing streak and starter Jimmy Garoppolo coming off the worst game of his career, coach Kyle Shanahan still isn’t ready to make a change at quarterback — even if rookie and Marshall native Trey Lance is healthy.

Garoppolo turned the ball over three times and struggled to move the offense for most of Sunday night’s 30-18 loss to the Indianapolis Colts but will remain the starter when the Niners head to Chicago this week.

“We didn’t go into that game thinking that Jimmy was one bad game away from losing his job or anything like that,” Shanahan said Monday. “Jimmy didn’t play as good as he could. He knows that. I know that. I think it was some pretty hard circumstances for him, for both quarterbacks, considering some of the weather. I definitely thought he could have played better. But that was not a game where if Jimmy has one bad game he’s losing his job.”

Shanahan still called Lance the future for the Niners (2-4), but when the future arrives is unknown. San Francisco dealt three first-round picks to draft Lance third overall this spring, and he played a handful of snaps before taking over at halftime against Seattle on Oct. 3 when Garoppolo left with a calf injury.

Lance showed some positive signs in his only start the following week at Arizona but was inconsistent when throwing the ball and then sprained his left knee. He missed this past week but should return to practice at least on a limited basis Wednesday and could be used in a situational role.

Shanahan is starting to come under some heat as the Niners struggle in his fifth season. San Francisco has had one winning season since Shanahan arrived, going to the Super Bowl in 2019.

He had excuses early: a depleted roster when he arrived, and injuries in 2018 and 2020. This year was supposed to be different. Shanahan understands the current criticism.

“We’re sitting here at 2-4, we’ve lost four games in a row that I believe all four we were capable of winning, which is where you want to start,” he said. “You want to have a chance to win every game you’re in. … We have to find a way to win some of these close games that we’ve found a way to lose.”

What’s working

First drive. The Niners put together an impressive, scripted opening drive, moving 78 yards in eight plays to score on Elijah Mitchell’s 14-yard run. San Francisco used rollouts and bootlegs to great success on that possession, but struggled offensively for most of the rest of the game. The 49ers either failed to get a first down or committed a turnover on nine of their final 10 drives, not including a one-play sack that ended the game.

What needs help

Secondary. The Niners allowed two deep passes downfield in the wet conditions to Carson Wentz and once again struggled to defend cleanly. San Francisco committed five pass-interference penalties, with Emmanuel Moseley getting caught twice and Josh Norman, Jaquiski Tartt and K’Waun Williams once each.

Three of those penalties were accepted for 97 yards, helping set up two TDs.

“We gave them way too many explosive freebies,” Shanahan said.

For the season, the Niners have committed a league-high 14 pass-interference penalties, including three that were declined or offset. The 11 accepted penalties have given opponents 250 yards, the most in the league.

Injuries

S Jaquiski Tartt (knee) will miss a few weeks. … DE Dee Ford, LB Aziz Al-Shaair are both in concussion protocol. … CB Moseley left the game with a back injury but should be fine. … Shanahan hopes LT Trent Williams can return after missing a game with an ankle injury.

Key number

120. The Niners have committed 120 turnovers in four-plus seasons under Shanahan, including four on Sunday. That’s seven shy of Tampa Bay’s NFL-worst 127 in that span. Turnovers have led to 397 points for the opposition — the most allowed by any team since 2017.

Next steps

The 49ers visit Chicago on Sunday.