Arsenal were leading 2-1 when Saka was replaced by Leandro Trossard.

"We are pretty worried about Saka's injury," Arteta said after the match.

"He grabbed his hamstring and couldn't continue. He will have to be assessed but we are pretty worried, yes."

Saka, Arsenal's main attacking threat with 15 goal contributions in 15 league games, was sidelined earlier this season with a hamstring injury. He withdrew from the England squad in October before missing two Arsenal games, including a 2-0 defeat at Bournemouth.

Saka's muscle issue came after manager Mikel Arteta confirmed Raheem Sterling -- a potential alternative in midfield -- had picked up an injury in training, forcing him out of the squad to face Palace entirely.