Manchester United interim manager Ralf Rangnick says competition is the reason for Juan Mata's lack of playing time this season.

The Spaniard -whose contract expires at season's end - has made four fleeting appearances under Rangnick this season.

And Rangnick insists Mata remains an important member of his squad.

"Well, he is also very popular in our group," Rangnick said ahead of Tuesday's Champions League clash with Atletico Madrid.

"I think everybody likes Juan a lot, and he can still play on this level, but it's a question of competition.

"We have quite a few players for those midfield places and I will also have to decide and choose between five or six players for the places for tomorrow's game."