Juan Mata says the first red card of his career hurts so much more because it could have been avoided.

The Spanish playmaker was sent off for Manchester United in the first half of their eventual 1-0 loss to West Bromwich Albion on Sunday after first encroaching at a free-kick before a sloppy challenge on former teammate Darren Fletcher.

Regarding the sending off, Mata admitted it did not sit well with him but said it would be a good lesson learned.

"After almost 500 games as a professional player, this Sunday I was sent off for the first time in my career," he wrote in his weekly blog.

"As you can imagine, it's not easy for me to write these lines. The truth is this is a new and strange situation for me, but we learn from everything.

"I know that, in football, we see things like this every week, but obviously what hurts more is that my team-mates had to fight with 10 men for a long time.

"I have the feeling that both decisions were rigorous. We see more serious fouls that are not penalised in such a way. But at the same time I could have avoided them and I take responsibility.

"It also leaves me with a bad taste for the supporters who travelled to the stadium, and for those who were watching the game from home.

"I take responsibility in the good and the bad moments, as I've always done and I will always do."