Diego Costa admits he made a mistake when he threw his bit as Jose Mourinho.
Costa threw his bib in Mourinho's direction after he was dropped for the 0-0 draw at White Hart Lane and then sent out to warm up during the second half only to be told to sit back down with the rest of the substitutes.
"I have to improve a bit," Costa told Spanish radio station Onda Cero. "The start of the season has not been good for me -- not in how I have played nor in goals.
"I know I have to be better to go to Euro 2016 with Spain. I have to work hard and fight, but I know I have time to improve and I hope I will.
"The bib [incident] is in the past. I made a mistake, but my relationship with Mourinho is amazing, we get on really well. There are things you need to control, but the bib thing was an impulse.
"The truth is Chelsea haven't been in a great moment, above all losing the other day at home [against Bournemouth]. Today it was important to win to make the fans happy and to recover our confidence."