Chelsea defender Gary Cahill has said striker Didier Drogba is back to his best after three goals in his last three games for the Blues.
Stamford Bridge legend Drogba, who returned to the club in the summer, has spent most of his time on the bench following the summer arrival of Diego Costa from Atletico Madrid.
But an injury to Costa has given the 36-year-old his chance -- and a Champions League penalty in the 6-0 win against Maribor, a header in the 1-1 draw at Manchester United and a goal in the 2-1 Capital One Cup win at Shrewsbury have followed.
#INSERT type:image caption:Drogba celebrates after his header put Chelsea in front at Old Trafford. END#
Cahill told PA Sport he believed that would make it difficult for Costa to get back into the side when he returns to full fitness, adding: "He [Drogba] is fully fit now, he's looking sharp and dangerous. He was massive for us on Tuesday, and he got a vital goal.
"Who knows how long he can go on for? That's for the club and Didier to decide but, at this moment, we've started the season well and he's been a big part of that. What a character he is off the pitch.
"Obviously Diego is playing the majority of the games, but Didier is getting back to match sharpness."
Drogba's first spell at Chelsea saw him win three Premier League titles, four FA Cups and the Champions League in 2012. He left the club after scoring the decisive penalty in the Champions League final shootout victory over Bayern Munich.
Costa is expected to be fit for the visit of west London rivals QPR on Saturday after hamstring problems and a virus, but Cahill said he may not be able to step straight back into the team, adding: "There are options, not just up front but all over the pitch."
He stressed that the Blues must not to take struggling Rangers lightly, adding: "The onus is on us to be on the front foot. We need to prepare well and make sure we're fully focused.
"Last season, we struggled at times against teams people thought we were going to beat. It's never as easy as that.''