Juan Mata has insisted he is happy at Chelsea and never doubted his ability, despite a tough start to the season under Jose Mourinho.
The Spain international has not been a regular starter at Stamford Bridge this term and has come in for criticism from his manager over his work-rate for the team.
He has not started in the Premier League since mid-September, but was named in the starting line-up for their 4-0 victory over Steaua Bucharest in the UEFA Champions League on Tuesday.
Mata admits it took him time to adapt to Mourinho's way of working, but hopes to now have a long run in the first-team.
"I think it's normal that we needed time (to adapt to the new manager), but we are doing that," he told the London Evening Standard. "I'm not the kind of man that gets down.
"I always believe in myself and train really hard. This is my way to behave, to be positive as much as I can.
"I have really enjoyed playing for this club in the last two seasons. I know what I can give to the team and I'm just trying to do that.
"I have to do this (to adapt to what Mourinho wants). I try to do my best in every game and I think I'm doing that. I enjoyed playing against Steaua, we all did, and I'm calm."
Victory in Romania helped Chelsea bounce back from their disappointing defeat to Basel in the opening game of Group E, and Mata hopes it will be a springboard for them to keep on improving.
"We have to keep going and take advantage of this victory, to keep winning," he added. "I'm sure the best is still to come from the team.
"I think we have a good squad and have signed young players this season. We will get even better in the future. The last few games have been good and we are building momentum.
"It was very important for us to win against Steaua after the defeat against Basel. For us it was like a final because we needed to win and we showed that from the first minute."