United States and AC Milan attacker Christian Pulisic was kept out of the matchday roster for a Serie A loss to Atalanta on Sunday with a minor injury.
Sources confirmed to ESPN that Pulisic sustained a muscular issue to his glute during the club's final training session on Friday before the match.
A source with knowledge of the situation said they didn't believe that the injury was serious, and that Pulisic's withdrawal was "precautionary" in nature. Italian media reported Pulisic will undergo medical tests on Monday.
The injury comes at a bad time for Pulisic, with the World Cup just a month away. U.S. manager Mauricio Pochettino is due to announce his final World Cup roster for the USMNT on May 26.
Pulisic, who has not scored for Milan in a career-high 17 league matches since Dec. 28, has a long history of picking up muscle injuries. According to Transfermarkt, he has had four different muscle injuries this season alone that have forced him to miss a combined total of 56 days.
The 27-year-old is a doubt for Milan's penultimate match at Genoa next weekend but could be back for the final game of the season, at home to Cagliari, the following week.
The player's importance to the USMNT can't be underestimated, as he remains the most dynamic attacker in the player pool. If Puliisc were unable to participate in the World Cup that would serve as a massive blow to the team's aim of a deep tournament run.
The USMNT will begin its pre-World Cup training camp in Atlanta on May 27, the day after the roster is announced. The U.S. team will then play pre-tournament friendlies against Senegal in Charlotte, N.C. on May 31, and Germany in Chicago six days later. The USMNT's first World Cup match is against Paraguay on June 12.
Gianluca DiMarzio was the first to report the news of Pulisic's injury.
The 3-2 loss to Atalanta leaves Milan, who have had a disappointing season on all fronts, in jeopardy of missing out on Champions League football next season. They still occupy the fourth and final spot, but both Roma and Como are hot on their heels with two games left to play.
Information from The Associated Press was used in this report.
