(CNN) -- Manchester United have hit back at Owen Hargreaves after their former midfielder claimed he had been mistreated by the English champions' medical staff.





Hargreaves, who joined United's archrivals Manchester City in August after his contract at Old Trafford expired, was reported in the British press as having said he felt like a guinea pig during an injury plagued four-year spell with the Red Devils.





The England midfielder was speaking after making a goal-scoring debut for City in their 2-0 Carling Cup win over Birmingham City on Wednesday.





"Manchester United is disappointed with Owen Hargreaves' remarks after the game on Wednesday," read a statement on the three-time European champions' website.





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"The club gave him the best possible care for three years and is as disappointed as anyone he was not able to play a part in the team's success at that time.





"It has shared all the medical records with Manchester City and is comfortable with the actions taken by its medical staff at each step of his many attempts at rehabilitation."





The Canada-born star arrived at United from German outfit Bayern Munich in 2007, but only made 27 appearances for Alex Ferguson's team due to persistent injury problems relating to the tendons in his knee.





"They said I would be fit for the start of pre-season but, after that, I never got back on my feet," Hargreaves was reported as saying in British newspaper The Guardian. "My tendon was never the same. They said my tendon was good, but it felt like I was made out of glass.





"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. That was surgery, and that was 18 months gone."





But United denied Hargreaves' claims, with the statement continuing to say: "United does not acknowledge any validity in the comments Owen is alleged to have made.





"Manchester United has some of the best sports medical staff in world sport, who have made a significant contribution to United's on-pitch success in recent seasons."





Prior to joining City, Hargreaves posted a series of clips on the video-sharing website YouTube aimed at proving his fitness.





The 30-year-old made his professional debut for Bayern in 2000, and went on to win four Bundesliga titles with the club and the European Champions League in 2001.





Hargreaves also represent England at both the 2002 and 2006 World Cups, and won a second career Champions League title when United beat Chelsea in Moscow in 2008.
What were his injuries? What did the Manchester United people say? What did Hargreaves claim? Who has hit back? Who joined the team? What is Owen's role? What team is he on? What did he join recently?
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