Kevin Pietersen accepts he has made mistakes in his dealings with England and admits his recent injury problems have left him "treading on eggshells" around team-mates.

The former Hampshire star made his competitive comeback for Surrey today, putting an end to three months on the sidelines with a right knee problem by taking the field in a four-day match against Yorkshire.

He marked the occasion by giving a revealing radio interview to his one-time best man Darren Gough, which was broadcast while he fielded at Headingley.

In it the increasingly elusive Pietersen alluded for the first time to the career-threatening dramas of last year, which started with his memorable "it's tough being me in this dressing room" press conference at the same ground.

Pietersen was then dropped from the Test side amid reports he had sent "provocative" messages to rival South Africa players and left out of the World Twenty20 squad before a period of reintegration that resulted in his return in all formats.

"I probably didn't go about it in the best fashion," Pietersen told Gough on talkSPORT.

"You make mistakes and you get over them and that's the way you grow as a human being, by learning from things that you don't do well.

"So I take it on the chin, no dramas, it's just a case of looking forward and making sure that you do the right things now."

Having declared himself fit, Pietersen has been fast-tracked back to the international stage and will play in the second Twenty20 against New Zealand at The Oval on Thursday.

He can then expect to play for England in their pre-Ashes warm-up against Essex before lining up in the first Test against Australia on July 10.

The 32-year-old is desperate to be back as a contributing member of the side, revealing he feels awkward in the team environment when he is unavailable to play.

"Injuries are a sportsmen's worst nightmare," he said.

"Having played for England for what, eight years, you know you're injured but you don't feel the same in the dressing room "You feel totally out of the system. It's just the feeling you get.

"If somebody's injured, whenever they come back in the dressing room and I'm fully fit you don't have that feeling towards them, but you are treading on eggshells as an injured player walking around the dressing room, thinking 'should I be here?'.

"I've played 94 Test matches and 100-and-however-many international one-dayers, Twenty-20s..I've been around since 2004 and you still get that 'Right, I'm an injured player' feeling. "Sport gets you in, and it gets you out real quick."

Pietersen, whose media appearances have been almost non-existent this year, also went into some detail about the fitness problems that forced him on to the sidelines.

"(It was an) extremely badly bruised bottom of the femur, the bone in the knee. It was really bad," he said.

"In New Zealand I couldn't duck a bouncer, I couldn't sweep, I was in all sorts of trouble. I was on the strongest painkillers and eventually my stomach just gave up with me in the second test match.

"I probably did it a lot of damage by playing, but I just tried to get through and played for as long as I could because I hate missing Test matches.

"A bruising on your bone is a lot worse than breaking it. You know with a break it'll be back.

"I've broken my arm, I've broken collar bones, I've broken my leg. I've broken plenty of bones and you know that within six, seven, eight weeks you're firing again.

"The bruising has been really frustrating but over the last three weeks I turned a real positive corner."