The San Francisco 49ers won their first game of the season Sunday, but they had to leave MetLife Stadium feeling like they might have lost.

Without many of their key players, the Niners delivered a gritty, resilient response to their Week 1 loss to the Arizona Cardinals, pasting the New York Jets 31-13. Given the circumstances, it was an impressive performance, even against the lowly Jets.

For as much as the victory had to feel good after the Week 1 disappointment, another series of devastating injuries cast an ominous pall over the Niners' hopes of defending their NFC championship.

It started in the first quarter with a left knee injury for defensive end Nick Bosa, who had to be taken to the locker room on a cart and was ruled out. Two plays later, defensive tackle Solomon Thomas also suffered a left knee injury and went to the locker room on a cart.

Then, quarterback Jimmy Garoppolo tried to play through a right ankle injury but only made it to halftime before his day was done. Running back Raheem Mostert suffered a knee injury and did not play in the second half.

All of that for a team that entered the game without tight end George Kittle (sprained knee), cornerback Richard Sherman (calf strain), receiver Deebo Samuel (foot fracture) and defensive end Dee Ford (neck spasms).

One of the hallmarks of the 2019 49ers was their ability to dive deep into their depth and find ways to win games. They did it again and again on their way to Super Bowl LIV. But, for as many injuries as last year's team had, they never faced an injury crisis like this.

Next week, the Niners return to MetLife Stadium and its new artificial surface to play the New York Giants. They'll have to think twice before asking someone like Kittle to play on it after what happened Sunday. From there, they'll return home to play the Philadelphia Eagles and Miami Dolphins.

Suddenly, a four-game stretch that once seemed to be a chance for the Niners to get back on track, now looks more like something to survive before the schedule intensifies.

QB breakdown: Garoppolo's ankle injury happened on the Niners' fourth offensive snap, but he pushed through it for the rest of the first half. After a rough outing last week, Garoppolo went 14-of-16 for 131 yards and two touchdowns for a passer rating of 140.4.

Things didn't go as well for backup Nick Mullens, who finished 8-of-11 for 71 yards with no touchdowns and an interception for a rating of 51.7. The lead was big enough that Mullens didn't have to do much to seal the win, but if Garoppolo's injury extends beyond this week, he will have to get back up to speed quickly.

Eye-popping NextGen Stat: For the second week in a row, Mostert proved himself one of the fastest players in the league. On the first play of the game, Mostert took a simple toss off the right side and raced 80 yards for a touchdown.

On the run, Mostert hit a max speed of 23.09 miles per hour, the fastest max speed by any ball carrier on a play from scrimmage over the last five seasons.