MILAN: United States forward Christian Pulisic missed AC Milan's Serie A match against Atalanta on Sunday with a lower back injury in another blow for the top American player, already struggling with poor form and a record goalscoring drought.

Pulisic felt a problem in Friday's training session and it was determined on Sunday that it was too serious to even have him on the bench. Italian media reported Pulisic will undergo medical tests on Monday. 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.

Milan lost 3-2 at home to Atalanta on Sunday — and was 3-0 down until the 88th minute — to leave it at risk of not qualifying for next season's Champions League. The Rossoneri are fourth, the final Champions League qualifying berth, level on points with fifth-place Roma and just two above Como.

Pulisic is not thought to be a doubt for the World Cup. The U.S. has friendlies against Senegal on May 31 and Germany on June 6, then starts Group D against Paraguay on June 12 in Inglewood, California. The Americans play Australia a week later at Seattle and conclude the group stage on June 25 back at SoFi Stadium against Turkey.