Marcos Alonso has said he is happy to stay at Chelsea despite a "tough season" and added that he has not let fan criticism affect him.
Reports in recent months have linked Alonso, who signed a contract extension in October, with a return to Spain after he struggled to hold down a starting spot.
Alonso said he had found it tough to adapt to Maurizio Sarri's instructions at times but saw his future at Stamford Bridge despite becoming a target for criticism from sections of the fanbase.
"Football is like this," he said. "The better team you play for, the more fans follow you, and there are millions of coaches and managers around the world!
"Some of them understand football one way, some of them have another opinion. I am the best to judge of when I play well and when I don't. Of course during the season you play some bad games, but it's been a good campaign.
"I'm always looking for more, looking to improve and get better. That's something inside me, I know I have to work for it.
"I don't really care about the critics. It can't affect you. I'm the one to trust myself and to look for more."
Alonso has had to accept sharing minutes at left-back with Emerson Palmieri in recent months, and said attempting to change his game to fit what Sarri wanted had a negative impact on his performances.
"For me personally, the path changed," he said. "I started very well, then the manager wanted different things from me.
"After that I was trying to do what he wanted and then he told me he wanted to play like I was at the beginning of the season, so maybe that has conditioned, a little bit, the way of my game.
"I think I'm settled now, I am very happy at Chelsea and looking forward to finish the season with a win and a cup [in the Europa League final against Arsenal]."
Real Madrid and Atletico Madrid have both been linked with Alonso, but the 28-year-old said: "There is always talk. It means I'm doing well if other teams are trying to get in touch.
"I am very happy here, but we will see what happens this summer. First of all I'm focusing on the final. I am very happy to have four more years here, and hopefully I will stay many more years here."