No Costa fear- Jose Mourinho

Diego Costa works out in training ahead of West Brom clash

Jose Mourinho has allayed fears over Diego Costa's fitness during the gruelling Christmas period, describing the Portuguese as an 'incredible marathon.'

Costa has struggled with troublesome hamstrings since he signed for Chelsea, an injury which Mourinho is confident is behind the striker.

Mourinho has been embroiled in an on-going row with Spain coach Vicente Del Bosque about how he has handled Costa during international breaks this year.

But Costa has worked with Chelsea physios during the past fortnight and Mourinho believes it has been the perfect preparation for them to play 12 games between now and New Years Day.

Mourinho said: 'I believe (this period has set him up for the rest of the season), but now we are going to have a period that is new for him. I believe the Christmas period for players doing it for the first time in their careers is more difficult.

'The English players, or those who have been here for many years, are more physically and mentally adapted and prepared to cope with the special incredible marathon of football we face. If you do it thinking, “I should be having Christmas with my family in Portugal, Brazil or France,” you can’t do it.

'Would I like a Christmas in Portugal? Yes, but there is a lot of positive things.