Brazilian-born midfielder Deco is doubtful for Portugal’s World Cup Group D opener against Angola on Sunday.
The Barcelona midfielder withdrew from training on Friday after picking up the injury in a clash with a teammate.
The news comes after the Brazilian-born star, 28, reportedly walked out of training on Thursday following a row.
The absence of Deco would be a major blow for Scolari, who brought Deco into the national team three years ago.
Portugal open their campaign against Angola before facing Iran and Mexico.