Thankfully for the San Francisco 49ers, Jimmy Garoppolo is healthy, but their tight end Garrett Celek isn't. The 49ers have suffered a brutal stretch of injuries since last year, including Garoppolo's ACL tear, and Celek is the latest to go down.

Celek recently had back surgery, 49ers coach Kyle Shanahan revealed after a recent minicamp practice, per David Lombardi of The Athletic. Shanahan said the surgery would likely sideline the veteran for around two months, which means he'll miss a lot of training camp.

In even worse news, the back issue apparently isn't the only thing Celek is dealing with. Shanahan also said that he's still in the concussion protocol from a concussion he suffered in Week 16 of last season. As Lombardi points out, the 49ers are now a bit thin at tight end beyond George Kittle.

Kittle is a bonafide star and one of the best tight ends in the league, but San Francisco is now lacking depth. Presumably the next man up on the depth chart would be second-year player Ross Dwelley. Dwelley played a very limited role as a rookie and caught two passes for 14 yards.

If something were to happen to Kittle at this point, the 49ers would be in big trouble. Celek has been with the 49ers since 2012 and is one of the veteran leaders on the team, so he's pretty important even if he doesn't have a huge role on offense. He caught five passes for 90 yards last season, but he had 336 yards and four touchdowns the year before.