New York Giants receiver Brandon Marshall is undergoing season-ending surgery Tuesday on his injured ankle, he announced on his Instagram account.

Marshall signed a two-year deal with the New York Giants this offseason. He had 18 catches for 154 yards and no touchdowns in five games this season.

Marshall was injured when he attempted to make a catch deep down the left sideline Sunday against the Los Angeles Chargers and landed awkwardly. The Giants said he was undergoing tests Monday to determine the extent of the injury.