LONDON - Chelsea manager Jose Mourinho says he is unsure when Diego Costa will return from injury and has attacked the Spanish national team for its treatment of the striker.

Costa, whose nagging hamstring problems are being carefully managed by Chelsea, missed the 2-1 win over Crystal Palace on Saturday after playing back-to-back games for Spain during the two-week international break.

In sarcastic comments to the BBC, Mourinho says "Costa went to the national team, he played two big matches against Slovakia and Luxembourg, and he came back in conditions where he's not available to play for his club.

Mourinho added Costa "will play for me when he has free time from the national team."

Costa has scored nine goals in seven league games for Chelsea, which is top by five points.