Chelsea manager Luiz Felipe Scolari expects to return from the pre-season tour of Asia and Russia with a fully fit Didier Drogba ready to help the club win back the Premier League crown. The frontman has been the focus of speculation over his future and stayed in London as the Blues set off for their pre-season tour, with Chelsea insisting he is recovering from a persistent knee injury. Drogba's injury status was confirmed by Scolari today after arriving in southern China ahead of his first game in charge of Chelsea, against Chinese Super League outfit Guangzhou Pharmaceutical on Wednesday. 'Didier is injured and the doctor and our medical staff put together a recuperation plan for him and he will be out for three weeks, maximum four weeks,' said the 59-year-old Brazilian. 'It was impossible for him to come with us to China.' Drogba's agent revealed last week that the 30-year-old will decide whether to sign a contract extension with Chelsea by Saturday. But former Portugal manager Scolari is confident the Ivory Coast striker and midfielder Frank Lampard will be in the Chelsea squad who will look to prise the title away from Manchester United and also lead a successful Champions League challenge. 'Didier's future is at Chelsea because he has a contract with us,' added Scolari. 'He has a contract with us and I think he is happy at Chelsea. He will follow a normal recuperation plan and I hope when we come back he will be in good condition.' While Drogba remains in London to recover at Chelsea's Cobham training base, Lampard made the trip to China with the rest of the squad, boosting hopes the 30-year-old will at least stay at Stamford Bridge until the end of his contract, which runs out next summer. 'He is training every day in the morning and afternoon very well. The most important thing is that he is here with us,' said Scolari. 'I have spoken to him every day, we are talking every day about Chelsea, about what's the best way for Chelsea to play and when he is training with the other players what's the best position for him. 'I have spoken about how to win games with Chelsea and Lampard and no more.'