AC Milan striker Alexandre Pato is likely to require several more weeks on the sidelines after tearing his thigh muscle at the weekend.
The Brazil international hit-man was substituted in Sunday's 1-1 Serie A draw at home to Napoli just 15 minutes into yet another comeback.
Pato has barely played for Milan this year due to thigh trouble and the Rossoneri are keen to establish the cause of the long-term problems.
The 20-year-old will undergo further tests in the coming days and it remains doubtful whether he will be included in Dunga's World Cup squad this summer.
"Tests have shown a tear," read a statement on the club's official website.
"Pato will undergo further checks in the coming days."