The Boston Celtics announced that Kemba Walker is doubtful to play in Monday’s game against the Sacramento Kings because of a neck sprain he suffered Friday night in Denver. Winslow Townson/Associated Press

The Boston Celtics announced on Sunday that guard Kemba Walker is doubtful to play in Monday’s home game against the Sacramento Kings with a neck sprain.

Walker ran head first into Semi Ojeleye in the second quarter of Boston’s loss to the Denver Nuggets on Friday night. He was taken off the court on a stretcher and evaluated at the arena. At that point, the Celtics said Walker was suffering from concussion-like symptoms, but it was apparent that he had avoided a more serious injury.

“All the scans that he went through at halftime yielded good results,” Coach Brad Stevens said after the game. “I saw him in the ambulance at halftime that took him to the hospital and he had his wherewithal and was in decent spirits, which was good, obviously.”

He was released from the hospital a few hours later and was healthy enough to travel back to Boston with the team. It’s unclear if the concussion-like symptoms remain.

“It hurt and seeing anybody carried off on the stretcher after getting hurt like that, it’s tough,” Marcus Smart said after the game. “We’re just glad he’s OK and it’s not too serious. He’s going to recover. Our prayers are up for him. We hope and wish him get well very soon, but it’s a scary thing to see.”

The 29-year-old Walker, who was a free-agent acquisition by the Celtics this summer, is averaging 21.1 points, 4.7 assists and 4.6 rebounds in 15 games. He was a third-team All-NBA selection last season with the Charlotte Hornets.

Walker becomes the second key Boston player dealing with an injury. Gordon Hayward broke his left hand in a game at San Antonio on Nov. 9, and is not expected back in the lineup for at least a month.