WARNING: GRAPHIC CONTENT

An NFL player has stood up to celebrate a long pass completely oblivious to a dislocated ankle suffered when he was taken down by a hip-drop tackle — the same injury that took down NRL great Nathan Cleary.

Kansas City Chiefs wide receiver Tyquan Thornton suffered the gruesome injury to his left leg during the fourth quarter against the Las Vegas Raiders on Sunday (Monday AEST).

Know the news with the 7NEWS app: Download today

Thornton’s left foot bent awkwardly under Raiders safety Treydan Stukes as they both hit the turf after Thornton hauled in a 55-yard pass from Patrick Mahomes.

Thornton left on a cart as players from both teams knelt in prayer.

Kenneth Walker III ran for a two-yard touchdown for the Chiefs on the next play.

The injury ended a huge day for Thornton, who had five catches for 111 yards and two touchdowns.

He caught an eight-yard pass from Mahomes earlier in the fourth for his second TD to put the Chiefs ahead 17-13 and they went on to win 24-19.

“I’m just praying for him,” Mahomes said when asked about Thornton after the game.

“You never want anyone to get injured and you’re hoping it’s better than it looked out there. Praying for him and hopefully he comes back healthy.”

The full extent of Thornton’s injury is not yet clear.

Cleary suffered a gruesome compound fracture and ankle dislocation when he was tackled by Newcastle’s Phoenix Crossland in the NRL preliminary finals late last month.

The hip-drop tackle led to a four-game ban for Crossland.

Cleary underwent surgery on his ankle before going back in for an operation to fix his unrelated broken right foot.

So gory was Cleary’s injury, one Penrith official compared it to a gunshot wound when he returned to the sideline after the halfback was stretchered off on Sunday.

“It was really difficult to watch,” Sydney Roosters veteran Daly Cherry-Evans said a day later, having been watching the game on TV.

“I’m sending out all my love to him and his recovery process. I hope it goes really smoothly.

“I watch it through the lens sometimes as a dad, and watching his dad (Ivan) up in the coach’s box, I just could not believe how he would be able to sit there, compose himself, and coach a side when his son has just had a pretty rough injury.”