Spaniard is yet to find his best form since joining Manchester United.
Manchester United's record signing had to watch on from the sidelines in midweek due to being cup-tied in the Champions League, as his teammates put their Liverpool horror show behind them.
He is expected to come back into the side this weekend against West Ham in the Premier League, but whether he should is another matter.
Robin van Persie's knee injury may create space for Danny Welbeck to start up front and make David Moyes' decision who to take out for Mata that little bit easier.
The Spaniard's form however has not been great since his arrival, not terrible, but he hasn't found his groove yet nor really his best position.
While he delivered three assists in his first four appearances in a United shirt, the performances were not sensational, but did show him capable of contributing even when not playing especially well.
Against Liverpool at the weekend he offered nothing, and will be keen to put things right if he does get a chance this coming weekend.
There are however two particular elements of Mata's game, which his form at Old Trafford illustrate need correcting, if he is to improve:
|Player||Team||Pos||Dispossessed / apps||Poss Lost All / apps||Apps||Mins|
|Juan Mata||Man Utd||MF||3.71||15.86||7||607|
|Shinji Kagawa||Man Utd||MF||2.50||10.00||10||602|
|Wayne Rooney||Man Utd||FW||2.25||19.92||24||2,026|
|Adnan Januzaj||Man Utd||MF||2.23||13.64||22||1,328|
|Danny Welbeck||Man Utd||FW||1.63||7.84||19||1,182|
|Marouane Fellaini||Man Utd||MF||1.55||8.82||11||700|
No Manchester United player this season is dispossessed as frequently as Mata, robbed off the ball more than two times per game more than Danny Welbeck.
Only one player loses possession more times per game than Mata, and that's Wayne Rooney, whose wayward passing at times is a flaw of his own game which he has never been able to truly eradicate.
United's average possession percentage is the sixth best in the Premier League on average, but below rivals Manchester City, as well as Arsenal and Everton.
While they need to work out ways to utilise the ball better, and Mata trying to prise open defences will always carry a higher risk-reward element than a player who plays it safe, his challenge is surely to be more accurate and his teammates to get into positions to help him flourish.
Is this a cause for concern regarding Mata? Well it may be a sign of his overall struggle to find a real place for himself in the United side. After relatively bright start, he has no goals or assists in his last four matches; and it's time for him to start justifying his record fee and show he was not an ill fit for the Red Devils.