Earlier this week, 49ers head coach Kyle Shanahan indicated that a decision would be made closer to the matchup because of Kittle's tendency for playing through injuries. But with Kittle missing practice all week and a cross-country flight to visit the Jets, the team opted to declare Kittle out with a sprained left knee.
Kittle will remain in San Francisco this weekend to rehab the knee injury and will rejoin the team next week as they prepare for their Week 3 matchup against the New York Giants.
"I think if it was just the normal person, we would have ruled him out earlier in the week, but we never do that with George because of what he's shown us here over these three years with him," Shanahan told reporters Friday. "We would have held out two more days to wait and see if it was a home game, but with us having to travel today we had to decide whether it was worth it to bring him.
"If he's not going to play, it's much better to leave him here for a couple days and let him get his rehab and everything. So, we had to make that decision a little bit earlier today. That will help him and he'll meet us in West Virginia and hopefully these two days staying here will help him and hopefully he'll be ready to go next week."
Kittle suffered the knee injury in last week's loss to the Arizona Cardinals. Right before halftime, 49ers quarterback Jimmy Garoppolo threw a high pass to Kittle, who was hit immediately by Cardinals defensive back Budda Baker.
Kittle limped off the field and entered the locker room but returned and played the entire second half. Garoppolo didn't target him in the third and fourth quarters. Kittle finished with four receptions for 44 yards on five targets.
In Kittle's absence, the 49ers will turn to backups Jordan Reed, Ross Dwelley and Charlie Woerner.
The 49ers (0-1) kick off against the Jets (0-1) at 1 p.m. EST Sunday at MetLife Stadium in East Rutherford, N.J.