Jeffries has hyperextended right knee
It was unclear when Jeffries was injured. The Knicks announced the injury at halftime on Thursday night and said the forward did not return.
He is scheduled for an MRI on Friday.
Jeffries had five points and two steals in the Knicks' 106-104 loss.
Information from the Associated Press was used in this report
MORE NBA HEADLINES
- Lump of coal: Durant (ankle) to sit vs. Spurs
- Veteran Smith: 'Excited to join Rockets'
- Cavs lose Varejao for year with torn Achilles
- Rockets sign McHale to 3-year extension