Owen Hargreaves has hit out at the medical treatment he received at former club Manchester United claiming he was used as a “guinea pig” for most of the procedures.

The former Bayern Munich midfielder made a dream debut for Manchester City in this week’s Carling Cup game against Birmingham and has now revealed that specialists have told him the treatment he received at United for his knee troubles was wrong on a number of levels and he felt he was “made out of glass” during his spell at Old Trafford.

He told The Guardian:

“I’ve had to be a guinea pig for a lot of these treatments. But when you’re left to try to make something of a difficult situation, it’s not really an option to say: ‘Let’s sit it out and rest for six months.

“I’m not a guy who wants to bitch and complain. I was trying to make the most of it, but it deteriorated over the season and we had to do these injections. My knee, my tendon, was never the same. They said my tendon was good, but it felt like I was made out of glass.

“With hindsight it’s a lot easier. And, yes, the injections I had I probably should not have had.

“We treated it and it got significantly worse through the injections. That obviously had a huge impact. Basically, I was left to pick up the pieces, which was incredibly frustrating.

“They said it [the injections] would help and that I wouldn’t have any side effects. That obviously wasn’t the case and, if I’d known I could have had a reaction like that, I wouldn’t have done it. It’s my career – I’m in it.

“I’m trying to get all this information. I’m hearing about tendons and, before, I didn’t know anything about tendons. I mean, I knew I had one, but I didn’t know its real function. It was a s*** position to be in, to be honest.”

Hargreaves has also risked the wrath of former manager Sir Alex Ferguson by claiming he was brought back into first-team action rather prematurely and he always knew he was going to get injured sometime during his long-awaited comeback.

He claimed:

“I started that game with two muscle injuries but I should never have been in that position to begin with. I was just going to try to get through 45 minutes because that would have been a start. But I didn’t even last five. I wasn’t surprised.

“I’d said to them that I had a hamstring problem, which I obviously did. I said: ‘I think I’ve got a bit of a problem here.’ I was surprised it didn’t go in the warm-up, to be completely honest.

“There were 70,000 people there and, if I had walked away from the game, it would have looked like I didn’t want to play. I thought: ‘I’ll try to play, I just won’t sprint.’ I know it sounds comical.”

Hargreaves has already been dreaming of making a comeback for England but he’ll have to defy a lot of critics to keep fit and prove his worth to both club and country.