The Red Devils are in runners up spot and 16 points adrift of Premier League leaders Manchester City in the one-sided title race.
Manchester United are only two points ahead of bitter rivals Liverpool FC in what promises to be a competitive battle for a top-four spot.
Jose Mourinho’s side lost 2-1 to Spanish side Sevilla in the Champions League round of 16 to underline the importance of their final eight Premier League games.
Manchester United have lost two of their last six Premier League games to raise some questions about their style of play under Jose Mourinho.
Swansea have looked rejuvenated under Carlos Carvahal and the relegation candidates are unbeaten in five of their last six outings in the English top flight.
Mata warned his Manchester United team-mates not to underestimate the Welsh side at Old Trafford on Saturday afternoon.
“We will play at Old Trafford against Swansea and a victory would be very important to show that we want to maintain our position at the table,” Mata wrote on his personal blog.
“Then, we will have plenty of time to think about the derby and the rest of the games ahead.”
Manchester United finished in sixth place in the Premier League table last term.
The Red Devils won the Europa League and the League Cup in Mourinho’s first season in charge at Old Trafford.
The 20-time English champions haven’t won the title since 2013.
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