49ers' Samuel hospitalized with pneumonia

San Francisco 49ers head coach Kyle Shanahan announced Monday that wide receiver Deebo Samuel is in the hospital while dealing with a form of pneumonia, according to ESPN's Nick Wagoner.

Samuel had fluid in his lungs and was struggling to breathe Sunday, said Shanahan, who added there's no timeline for the wideout's return. He was hospitalized Sunday night.

Hours before kickoff against the Kansas City Chiefs on Sunday, the 49ers announced Samuel was dealing with an illness but would still be active for the matchup.

The 28-year-old was only on the field for four offensive snaps and didn't register any catches or rushing attempts before the 49ers eventually ruled him out in the second half. Cameras showed Samuel jogging and seemingly coughing multiple times on his way to the locker room.

Samuel ranks second on the team with 39 touches this season. He's caught 20 passes for 335 yards and one touchdown while adding 51 yards and one TD on 19 attempts on the ground.

The 49ers also saw No. 1 wide receiver Brandon Aiyuk go down against the Chiefs. He's expected to miss the remainder of the season after tearing his ACL and MCL.