SANTA CLARA — With a first-year coach and some uncertainty at quarterback, the New England Patriots were expected to endure some growing pains early this season.

For the defending NFC champion San Francisco 49ers, back-to-back losses the past two weeks were a jolt for a team with legitimate hope of making it back to the Super Bowl.

The Niners (1-2) look to get back on track Sunday when they host the Patriots (1-2).

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49ers Seek to Rebound After Tough Losses

“It’s been tough to sleep the past couple of nights,” defensive end Nick Bosa said about the feeling from last week’s loss to the Los Angeles Rams. “Just mind racing. Always this time of year, I’m itching to get to Sunday, but after that, it’s major.”

It has been a challenging start to the season for the 49ers, who had contract disputes that kept stars Trent Williams and Brandon Aiyuk out of training camp practices, dealt with first-round pick Ricky Pearsall getting shot in the chest nine days before the season opener and have had to play without playmakers Christian McCaffrey, Deebo Samuel and George Kittle already this season.

Kittle is expected back this week, which should provide a boost to the offense. But the defense is where the biggest issues have been with San Francisco allowing 6.11 yards per play for the third-worst mark in the league.

“It’s not the standard that we have had since I’ve been here,” All-Pro linebacker Fred Warner said. “But I see the things that are positive on tape and we just need to clean up things that are negative.”

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Patriots’ Offense Struggles Under New Coach

They might have found the perfect opponent against whom to clean up those problems with the Patriots’ offense ranking near the bottom of the league in the first year under coach Jerod Mayo.

New England ranks 30th in the league averaging 4.15 yards per play and has the least prolific passing offense at just 130 yards per game with journeyman Jacoby Brissett keeping the quarterback seat warm before first-round rookie Drake Maye will likely take over at some point this season.

After a promising start with a Week 1 win at Cincinnati, the Patriots lost at home in overtime to Seattle and then were beaten 24-3 last week by the New York Jets when they were held to 139 yards of offense.

“It’s a work in progress as you go game-to-game,” Brissett said. “It’s like the whole thing. You’re closer than you think, but you also are farther than you believe, too, you know what I mean? It’s about that balance of being in between those two.”

Jennings Shines for 49ers

The big bright spot from the 49ers’ loss was the performance by receiver Jauan Jennings, who had 11 catches for 175 yards and three touchdowns. He joined Jerry Rice as the only players in franchise history to reach those marks in the same game.

“The numbers show it, but more than the numbers, he was a warrior the whole game,” coach Kyle Shanahan said.

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Patriots Grapple With Fumble Issues

Patriots running back Rhamondre Stevenson fumbled in each of the first two games and no one panicked because New England recovered both. When he lost the ball in the third game, though, it became a bigger concern.

“We always say that ball security is job security,” Mayo said.

Stevenson ran for more than 1,000 yards in his second season, but missed the last five games last year with a sprained ankle. He ran for 120 yards in the opener against Cincinnati and 81 more in Week 2 – on a total of 46 carries.

But Stevenson only carried six times for 23 yards in the 24-3 loss to the Jets last week and didn’t catch a pass for the first time this season. (He did break off a 29-yarder that was called back because he grabbed a defender’s facemask on a stiffarm.)

Mayo said Stevenson’s ability to stay on his feet makes him vulnerable to fumbling.

“Rhamondre is probably top-five in the league as far as breaking tackles. Now, that’s a dual-edge sword,” Mayo said. “You always want these guys to break tackles and try to make these big explosive plays, but in doing that, sometimes the ball gets loose.”

Special Teams Woes Plague 49ers

Special teams blunders played a big role in San Francisco’s two losses. The Niners had a punt blocked against Minnesota and then allowed a fake punt that led to a TD drive last week. There was also a missed 55-yard field goal by Jake Moody and a 38-yard punt return that set up the game-winning field goal.

“I would always love to make plays and stuff on special teams, but the biggest thing is to not be one of the reasons that you lose,” Shanahan said.

Patriots’ Offensive Line Struggles

Brissett was sacked five times and hit 10 in the loss to the Jets, and rookie Drake Maye was taken down twice in the final series after he came on to mop up.

That’s nothing: Brissett was sacked 10 times when he was playing for the Colts in 2017 in a 27-0 loss to Jacksonville (four weeks after he was sacked eight times in a loss to Tennessee).

“I just keep getting up,” he said. “Keep battling. It’s hard to see the light at the end of the tunnel, but it’s coming. … My confidence doesn’t change with the O-line. The plays are going to come. They’re going to settle in.”