Anthony was hurt during the first quarter while on a fastbreak. After throwing a pass to teammate Tyson Chandler for an alley-oop dunk, Anthony limped down the other end and grabbed his groin.
The Knicks said before Tuesday's practice that Anthony could be out up to two weeks.
Anthony has already battled through ankle, thumb and wrist injuries this season. He has missed three games because of the various ailments, but is still averaging a team-best 22.3 points with 6.0 rebounds and 4.2 assists in 22 games.