Ireland legend Paul O'Connell has announced his immediate retirement from rugby after failing to recover form a hamstring injury suffered at last year's Rugby World Cup. The 36-year-old former Ireland captain had been hoping to return to playing following the serious injury but has been forced to admit defeat and his contract with French club Toulon has been cancelled without playing a game. He won three Six Nations titles with Ireland including a Grand Slam. In his club career, he played for Young Munster before joining Munster and winning two European Cups as well as three Celtic Leagues. O'Connell took over as Ireland captain from Jamie Heaslip in 2013. He made his provincial debut in August 2001 and six months later earned his first cap in an Ireland jersey. In a statement, O'Connell said: "It is with deep regret that I have decided to retire from professional rugby following medical advice. I would like to take this opportunity to thank all at Rugby Club Toulonnais for thei