Dave Kitson has accused Stoke manager Tony Pulis of not giving him a proper chance at the Britannia Stadium.
Pulis paid a club record £5.5million for the Reading striker in July. But the 29-year-old, touted as a potential England player a year ago, failed to score a single goal and is now back with the Royals on loan.
Kitson insisted that was down to being played out of position. He said: 'I never got the chance to show what I can do. There were times when I was wondering why I had been brought to the club.
'I'd been bought for a lot of money but wasn't used the way I thought I was going to be.
'I was given 10 games. One I was played left midfield and the majority of the others centre midfield and you'd have to ask Tony Pulis why that was.
'I just became bemused after a while. When I look back on my career I'll deal with my time at Stoke by saying "that didn't happen".'
Kitson was one of a number of players who left Reading as soon as they were relegated from the Premier League last season.
He said: 'I felt I needed to be in the Premier League and I hold my hands up now and say that was a mistake.
'I was already at a club where I was wanted and my family were happy and I threw all that away for a new challenge because I felt that was what I needed.
'I was wrong and that was my fault. Nobody forced me to go to Stoke. It was the worst footballing decision I've ever made.'
Kitson insisted he had no personal grudge with Pulis, who signed James
Beattie for £3.5million in January and was immediately rewarded with goals.
He said: 'Tony Pulis is very interesting and forthright and a decent bloke. I'd have a beer with him any day of the week.'