Juan Mata has apologised after being sent off for the first time in his career in Manchester United's defeat at West Brom.
The midfielder collected two yellow cards in just 158 seconds during the first half of United's 1-0 loss at The Hawthorns on Sunday.
Defeat was a huge blow to United's Champions League hopes and they are three points behind fourth-placed rivals Manchester City, who have a game in hand.
United now face a crunch month with Europa League last 16 meetings against Liverpool while also playing West Ham and City.
Mata walked after just 26 minutes following two yellows for blocking a free-kick and a wild swipe at Darren Fletcher and has said sorry for leaving his team-mates in the lurch at The Hawthorns.
"After almost 500 games as a professional player, this Sunday I was sent off for the first time in my career. As you can imagine, it's not easy for me to write these lines," the Spain international wrote in his blog.
"The truth is this is a new and strange situation for me, not easy to assimilate, but we learn from everything. I know that, in football, we see things like these 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; that, in many occasions, 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, but I must carry on as always and from now on I'm already focused on the next game, the derby against Liverpool in the Europa League.
"In this sport there's no time for celebrations or moaning, and after last Wednesday's joy for the win and the goal against Watford, now I have to go through a more bitter experience. That's the way it is. What matters is to move forward and to always learn from each situation. And so I will."
Salomon Rondon scored a second-half winner to move West Brom onto 39 points and boss Tony Pulis believes the striker and Saido Berahino are forming a fine partnership.
"We've looked better of late - we have Saido and Salomon together. Since they've played together we've gelled a lot more," he said.
"Salomon never stops - he's a fantastic lad and his goal was a great finish."