Didier Drogba faces a race against time to be fit for the start of the new season after Chelsea confirmed the Ivory Coast striker underwent groin surgery.

The 32-year-old netted 29 goals last season, despite being troubled by the problem. Chelsea, though, hope the "minimally invasive surgery" will give Drogba the best chance of returning to action in good form.

However, the striker will need some three weeks recovery before he can return to training - which makes Drogba a major doubt for the Community Shield against Manchester United at Wembley on August 8 and the Barclays Premier League opener at home to newly-promoted West Brom.

A Chelsea statement read: "Didier Drogba successfully underwent minimally invasive surgery yesterday on the groin injury that had troubled him for some of last season.

"The decision to perform the procedure after his return from the World Cup was made to optimise his rehabilitation, and he is expected to return to full training in approximately three weeks."

Drogba had only just been passed fit to play in the World Cup after suffering a broken arm in the run-up to the tournament, but could not help prevent the Ivory Coast going out after the group stage.

This latest setback is a blow to Carlo Ancelotti, who is also likely to be without centre-half Alex and goalkeeper Petr Cech for the start of Chelsea's title defence.

The Blues are already well into their pre-season schedule, and are set to play Eintracht Frankfurt on August 1. A young Chelsea side were beaten 3-1 by Ajax in Amsterdam on Friday, where reserve keeper Ross Turnbull was guilty of some poor handling.

"We just have to hope Cech recovers quickly, but we have two other goalkeepers and have to keep faith with them," said Ancelotti.

"Everyone could see Turnbull didn't have a good performance, but that can happen to any young keeper and I still trust him."