David Moyes has endured a disappointing first season at Old Trafford after being charged with the task of replacing the legendary Alex Ferguson, with the Premier League champions seventh in the table and facing up to the prospect of missing out on top-four finish.
United's misery was compounded by a humbling 3-0 defeat to rivals Liverpool at Old Trafford, with a brace of Steven Gerrard penalties and a Luis Suarez strike condemning United to a fifth home defeat of the season in the top flight.
Moyes has also seen his side exit the League Cup and FA Cup this season, and United must overturn a 2-0 first leg deficit against Greek champions Olympiacos if they are to reach the UEFA Champions League quarter-finals.
Attacking midfielder Mata - who joined United for a record £37.1 million fee in January - was left to reflect on another frustrating performance, but the Spain international is confident United will come good.
"The storm will pass and the sun will rise again. I have no doubt," said Mata wrote in his personal blog.
"Besides, no one said this would be easy but this is football. It gives you fantastic moments but also very hard times you have to cope with, when you have to show pride and professionalism until the end.
"There are no words to describe your (fans) support in the stadium. In games like yesterday it makes me mad not being able to give you what you deserve.
"I know there is nothing I can say right now but at least I want you to know how I feel."
