Having prevented arch-rivals Manchester City from toasting a title triumph on derby day at the Etihad Stadium, the Red Devils surrendered the crown a week later in a shock 1-0 defeat to West Brom.
Those two outings, against top and bottom in the table, have highlighted the flaws and inconsistencies which still exist at Old Trafford.
Mata is, however, aware that a testing campaign can end on a high, with second spot up for grabs and more silverware on the line after reaching the semi-final stage of English football’s oldest knockout competition.
The Spain international told MUTV in the wake of a disappointing home reversal against West Brom which gifted the Premier League crown to City: "Second position was not done before the game. It was not done even if we won.
“It is even more important for the next games and we know we have to compete until the last week.
“It’s been a long season but we need to make sure we can compete until the end, that we keep that second position and we fight for being in another FA Cup final and try to win it.”
Mata added, with a Wembley showdown against Tottenham fast approaching: “It's the FA Cup, we all know how important it is.
“And then to get second in the league which is not the ideal position, but it’s the position we want to finish now.”
United will need to perform considerably better against Spurs than they did when hosting West Brom if they are to secure a shot at major silverware, with Mata conceding that the Red Devils deserved little from a meeting with the relegation-threatened Baggies.
He said, after seeing a solitary effort from Jay Rodriguez down Jose Mourinho’s men: “We are frustrated ourselves with the performance and what we have to do is think about the next game and keep going, because we have very important weeks ahead.
“It’s one of those days that we didn’t play good enough and we tried to create some chances in the first half and in the beginning of the second, but we didn’t play quickly enough.
“We made life quite difficult for ourselves so we are all frustrated, and we understand the frustration of the fans.”
United travel to Bournemouth in the Premier League on Wednesday, before heading to London to take on Tottenham in the FA Cup semi-finals on Saturday.