SANTA CLARA, Calif. — The 49ers were without star forward Christian McCaffrey for Monday night’s game against the Jets, but it didn’t matter.

McCaffrey was announced as a surprise inactive player before the game. The 28-year-old had been battling a calf injury that cost him four weeks of training camp, but he was back in training and expected to play.

Even without McCaffrey, the 49ers rolled to a 32-19 victory over the Jets. The 49ers had 180 yards rushing to go with 147 from backup Jordan Mason.

“They just beat us up front,” Jets coach Robert Saleh said.

The 49ers listed McCaffrey this week as having a calf/Achilles injury, which raised some eyebrows. But McCaffrey told reporters on Friday that his calf was feeling “a lot better” and that his Achilles is “not an issue for me.”

McCaffrey said he had no doubt he would play against the Jets. Mason was making his first career start in place of McCaffrey, who is the reigning AP Offensive Player of the Year and rushing champion.

McCaffrey had 1,459 rushing yards on 272 carries and 14 rushing touchdowns. He also had 564 receiving yards and seven receiving touchdowns.

The Jets have talked all week about preparing for McCaffrey. While the 49ers have a lot of talented offensive players, McCaffrey is the undisputed top weapon for San Francisco.

There was a strange sequence in the second quarter where CB Sauce Gardner was on the sideline for nine plays. Gardner was on the sideline with his helmet on and the Jets said it was not injury related. After the game, Saleh and Gardner said he was trying to catch his breath, which seemed like a strange explanation.

“It was a tackle I made and I just had to get my breath back,” Gardner said. “When I felt like I was good, I went back out on the field.”

CB Michael Carter II left the game in the fourth quarter with an ankle injury, just days after the Jets gave him a three-year contract extension. Saleh said Carter could have returned to the game, but the Jets were being cautious. Saleh revealed that Carter’s ankle injury during training camp was a high ankle sprain, an injury that can linger.

“It’s something he’ll have to deal with all year,” Saleh said.

The Jets signed OL Jake Hanson and LB Sam Eguavoen to the active roster off the practice squad for Monday night’s game. They also elevated TE Anthony Firkser and DE Jalyn Holmes from the practice squad. LB Zaire Barnes was placed on the injured list, meaning he will miss at least four games. The Jets also signed RB Kene Nwangwu to the practice squad. … The Jets’ inactives were RB Israel Abanikanda, CB Jarrick Bernard-Converse, DE Eric Watts, OT Max Mitchell, OT Carter Warren, TE Brenden Bates and DT Leonard Taylor. … Frank Gore, who played for the Jets in 2020, was an honorary captain for the 49ers.