Moyes concerned that Juan Mata will miss Champions League clash

With Manchester United scheduled to play Olympiakos in their next game in the Champions League, manager David Moyes admits that it is frustrating star midfielder Juan Mata will not be available for the crunch tie.

Mata will be missing as he is cup tied due to his previous commitments with former club Chelsea and the Spain international will be forced to watch from home as the Premier League champions take on the Greek giants Olympiakos.

Chelsea decided to part company with Mata in the January transfer window after he was deemed surplus to requirements and the attacking midfielder will only be available for the league campaign until the end of the season.

Mata is widely regarded as one of the best midfielders in the league and has made a huge different to Manchester United's campaign since his arrival.

"We wanted to get Mata when we could and that was the January transfer window," said Moyes.

"Yes, it's a frustration we can't use him in the Champions League and that's why you hear people saying January isn't a great time to buy.

"Most of the clubs are trying to buy players who aren't Champions League cup-tied."

United are odds on favourites to secure a victory over the Greek side and Moyes is expected to field Marouane Fellaini and Tom Cleverley in his midfield as a replacement for Mata. United will take on the Greek side on Tuesday as they prepare for the first game for their last 16 clash.