Shumpert will be evaluated in New York on Friday.
The third-year guard got his arm tangled with Washington guard Bradley Beal's arm as he drove late in the first quarter.
"A pretty uncomfortable feeling," Shumpert said after the Knicks' win over Washington. "But I'll be alright."
Shumpert said if Thursday's game was a regular-season contest, he could have played. He was told by team medical staff that he hit a nerve in his elbow.
"Hopefully it doesn't swell up. Hopefully everything's fine and I can play tomorrow," Shumpert said.
The former first-round pick was making his first start of the preseason on Thursday.
He had four points, including a left-handed putback dunk, two assists and two turnovers before leaving.
Shumpert's health is key for the Knicks. He is battling J.R. Smith for the starting shooting guard position.
Smith is currently rehabbing from offseason knee surgery. He hopes to play in the Knicks' final preseason game.
Once Smith is deemed healthy by the Knicks and an independent NBA doctor, he will have to serve a five-game suspension for violating the league's anti-drug policy.
PRIGIONI, TOO: Also, veteran point guard Pablo Prigioni left the game in the third quarter with a left elbow sprain. Prigioni said after the game that he hyperextended his elbow but it was minor and he felt "fine."