Mata, who returned from a groin injury to make his first start for United since March, believes his side were unlucky to lose at the Emirates, but must now switch their attention to Thursday night's all-important Europa League semi final second leg clash against Celta. The Red Devils take in a 1-0 aggregate after Marcus Rashford's winner gave United the win in the first leg in Vigo last week.
"Now we play Celta Vigo and we need to focus on that from this moment," Mata told MUTV. "We need to recover and focus on the second leg because we have the chance to play in a European final.
"We are fighting for a Champions League spot through the Europa League, but as well through the Premier League and we came here with this aim but unfortunately we couldn't win.
"We have a really important chance to play Champions League through the Europa League but in the Premier League anything can happen. We will try to win our remaining games and maybe we [will finish] in the top four."