United States national team captain Christian Pulisic was forced off the field with an injury during the first half of AC Milan's 2-1 loss to Atalanta on Friday.

The 26-year-old was replaced by Ruben Loftus-Cheek in the 38th minute of the match at Atalanta's Gewiss Stadium after appearing to slip awkwardly on the turf as he was fouled by Mario Pasalic.

The American, who had seen a shot saved earlier in the match, sat down on the ground in pain, touching his ankle and calf. Despite attempting to play through the discomfort, he signaled to the bench that he needed to come off. Pulisic was then helped off the field and replaced with the score tied at 1.

Ademola Lookman scored a late winner for Atalanta that sent the hosts to the top of Serie A and stretched their winning streak to nine games in all competitions.

In his second season with Milan, Pulisic has scored eight goals and provided six assists in 19 games.

Pulisic's injury is a concern for his club ahead of a crucial Champions League match against Red Star Belgrade on Wednesday.