Mata completed a �37.1 million ($61.2 million, 44.8 million euros) transfer from Chelsea on Saturday, making him the most expensive player in the club's history.

The 25-year-old Spanish midfielder was handed the number 10 role against Cardiff in support of striker Robin van Persie, who returned to the United team after a seven-week absence with a thigh strain.

Fellow striker Wayne Rooney, who has not played since a 2-1 defeat at home to Tottenham Hotspur on New Year's Day due to a groin problem, was named on the bench.

United approached Tuesday's game at Old Trafford in seventh place in the table, 14 points behind leaders Arsenal, after two defeats in their last three games.

"We just want to get back to winning ways tonight," said United manager David Moyes.

"Juan Mata is in. There's not too much pressure on him, but the way it panned out I felt we could start him. I don't expect too much too soon, and we don't expect him or Robin van Persie to last the full 90 minutes."