Juan Mata was left frustrated as Manchester United’s latest display of delayed intensity led to a drab defeat to Valencia, putting Jose Mourinho’s men on the back foot ahead of this Sunday’s trip to bitter rivals Liverpool.

With progress to the Champions League round of 16 already assured, the United boss made eight alterations to his injury-hit squad at the struggling LaLiga side.

But the fringe players failed their audition at the cavernous Mestalla, where a Phil Jones own goal compounded Carlos Soler’s first-half strike to render substitute Marcus Rashford’s effort a mere consolation as the visitors ended the match on top.

Wednesday’s 2-1 defeat meant United missed the chance to top Group H after Juventus surprisingly lost by the same scoreline at Young Boys, but this latest belated performance was more of a concern.

Mourinho’s men have more often than not only started playing after going behind – a point raised by Mata ahead of Sunday’s eagerly-anticipated Premier League trip to Liverpool.

“We are disappointed because obviously it’s more painful knowing that Juventus lost and if we’d have won we would have finished first in the group,” the former Valencia favourite said.

“Disappointing night. It was special for me personally coming back to Valencia and feel the love of the club and the supporters, so I am grateful for that.

“But disappointed overall. I think we reacted a bit too late, so we had some chances at the end that we could have scored.

“But overall we qualified and that was the most important thing and we knew that, but obviously we would have loved to have been first in the group.”

Put to Mata that goalscorer Rashford and Jesse Lingard had done well off the bench, Mata said: “Yeah, it seems like we always push in the last minutes, when players come off from the bench or the players that are on the pitch.

“It seems like we react in the last 10, 15 minutes and start creating more chances and getting closer and closer to score.

“That’s what we did today but it was not enough.”

That knack of only playing uninhibited football when the chips are down is a worrying quirk in a disappointing season, with United already 16 points behind league-leading Liverpool.

Defeat to Valencia adds pressure heading into Sunday’s clash with Jurgen Klopp’s Reds and Mata refused to use the excuse that the lack of occasion in Spain could have been behind a lack of intensity.

“It’s a very busy month and we have very important games coming, especially on Sunday,” the Spaniard told MUTV. “But I don’t think it’s an excuse because as a football player, you focus on the game that you are playing and try to give your best in every single game.

Manchester United v BSC Young Boys – UEFA Champions League – Group H – Old Trafford
Mata wants Manchester United to make stronger starts to games (Martin Rickett/PA)

“Today we were already qualified but it was still a Champions League game against a good team.

“Obviously, they wanted to show that they can beat a club like Manchester United and they are not in a very good position in the league either.

“But today they pushed, and they wanted to show they are a very competitive side.

“I know it’s difficult, but we have to keep going and especially with what we have coming on Sunday, we need to be ready for that.”