The Brazilian winger had to leave the game against Paris St Germain in the UEFA Cup on Thursday, just two minutes into the second half.
Hughes said: “We will check him out. With those kind of strains it is a minimum of two weeks, possibly longer.
“But we hope he has not compromised himself too much with the injury. It is a blow to us because obviously we are a little bit light in midfield. We cannot afford to lose too many bodies there.”
