Juan Mata
Juan Mata scored a goal against Sunderland in an otherwise frustrating match for UnitedReuters

Juan Mata has admitted his disappointment at how Manchester United have begun life under new manager Louis van Gaal – but has demanded patience from supporters as "all changes need time".

After a 2-1 defeat against Swansea in the Premier League opener at Old Trafford, van Gaal's side draw 1-1 in their visit to Sunderland – leaving them in 13th place after securing one single point from his first two games in charge.

"I know this is disappointing, but as I said last week – because it's true – this is just the beginning of the season and there is still a long way to go. We must remain positive and confident, keep working hard and get better day after day," Mata wrote on his official website.

"I do think that changes need time. We are talking about a new project, with a new manager and a new style. There is going to be a transition and that new start is more difficult if you don't get good results. We would have liked to win the first two games of the season but that didn't happen, and all we can do now is to prepare the next game, try to get the three points and start a good streak."

Nevertheless, the Spaniard was one of few highlights in the frustrating game against Sunderland as he scored the only goal of his side following a good assist from Antonio Valencia.

"Personally I'm happy with my first goal of the season, but not completely since we couldn't win," Mata wrote.

"It's never easy to play at Sunderland, although after the game that point is not enough. We scored first but they equalised in a corner kick before the break, and we didn't manage to score again in the second half."

Meanwhile and with Angel Di Maria's arrival yet to be official, Mata hailed the signing of Marcos Rojo.

"I would like to welcome him and I wish him all the best with our club. I believe he can contribute a lot of good things to the team as he showed, for instance, in the last World Cup with Argentina."