(Reuters) - New England Patriots tight end Rob Gronkowski has a suspected punctured lung and is likely to miss Sunday's game against San Francisco, the NFL website reported on Monday.

Gronkowski is undergoing further tests to determine the exact nature of the ailment but was injured during the Patriots' 31-24 loss to the Seattle Seahawks on Sunday.

It was unclear when Gronkowski sustained the injury but he missed five plays after taking a big hit from Seattle safety Earl Thomas.

"That was a big hit - probably one of the hardest I've got hit in my career, for sure," Gronkowski told reporters on Sunday.

"It's a little tough to breathe, but once it comes back, you're good. He hit me fair and square. It's football."

On the game's final play, Gronkowski and Seahawks safety Kam Chancellor got tangled up in the end zone on an incomplete pass.

Without the four-time Pro Bowler, New England will turn to Martellus Bennett, who recorded seven catches for 102 yards against Seattle.

(Writing by Jahmal Corner in Los Angeles, editing by Nick Mulvenney)