David de Gea's excellent performance in Manchester United's Europa League defeat at Liverpool is a bad sign for the team, says Juan Mata.

United put in a limp performance against their fierce rivals at Anfield going down 2-0 in the last-16 first-leg tie, which was the first meeting between the teams in UEFA competition.

It could have been worse for Louis van Gaal's side had Spain goalkeeper De Gea not made a string of top-class saves to ensure United still have the opportunity to salvage matters at Old Trafford next week.

Attacking midfielder Mata praised his compatriot, but urged United to learn quickly from the poor performance.

"David was very good as always and that’s not a very good sign for us because it means that they had even more chances to score," Mata told United's official website. 

"We need to move on, we need to learn from this game and we need to come back next week stronger."

The odds may be against United making the quarter-finals, but Mata – who was captain at Anfield – insists the team's never-say-die attitude means they can still progress.

"We never give up. We will try to start from the first minute and try to score," he added. 

"Last season I think we beat them 3-0, so we can do it. It's going to be tough because they are a good team with a good manager, but we could do it with our fans at home."