Dutch winger Arjen Robben admits he is uncertain when he will make his return to action for Bayern Munich.
The 26-year-old tore a muscle while playing in a friendly for Holland just before the World Cup but remained in the squad and helped his country reach the tournament's final.
But he then aggravated his muscle in his left thigh playing for the Bavarian giants during pre-season training and is still unsure when he will return.
Robben told BILD: "I am injured at the moment, I am unable to help the team progress at present.
"I am not sure when I will have the chance to return to action - it could take two weeks or two months as far as I am concerned."
Bayern have endured a stuttering start to the defence of their Bundesliga crown in the absence of Robben.
Louis van Gaal's side have only taken eight points from their opening six games and currently sit ten points off leaders Mainz after suffering a 2-1 home reverse to their opponents at the weekend.
Mainz have won all six games so far but Robben believes it is early days and all that matters is who is top of the Bundesliga at the end of the season.
He added: "Mainz are a good team, but everyone needs to be patient to see if they are able to keep that pace up.
"The most important thing remains that we are the team that is on top of the table when the league comes to an end. Champions are usually going to be made throughout the second half of a season."