Flyers forward Jaromir Jagr has a mild left groin strain and will miss seven to 10 days.
Jagr, 39, left the Winter Classic with a leg injury on Monday.
He is in his first season with Philadelphia after three in Russia.
Jagr has 12 goals, 31 points and is a plus-12 for the Flyers, who now trail the first-place Rangers by four points in the Atlantic Division.
Jaromir Jagr Out With Strained Groin