Diego Costa
Costa has been in prolific form this season, scoring 7 goals from 4 appearances in the Premier LeagueReuters

Didier Drogba feels that his strike partner Diego Costa was the missing piece in the Chelsea squad, and his addition has now made the Blues serious Premier League title contenders this season.

Costa, who completed a £32 million switch from Atletico Madrid to Stamford Bridge this summer, has been quite impressive for the Blues in the Premier League, scoring seven goals in four appearances.

Without the Spain striker, Chelsea struggled against Schalke in their opening Champions League fixture, where they were held to a 1-1 draw.

And Drogba, who started in place of Costa against Schalke, has backed the Spain international to lead Chelsea to glory this season.

"He is the striker we needed this season. When I look at him I can see the desire to win every challenge, and to score goals," said Drogba, according to ESPN.

"He is hungry for goals and that's the best thing for a team like us. For him to start this season in England, coming from Spain which is a different league and to recreate the same thing he was doing in Spain is fantastic."

Apart from just playing, Drogba, who has helped the Blues win ten major trophies during his first spell (2004-2012) at the club, says that he is also looking to act as a mentor to all the young players in the West London club.

"I'm here to help but I'm also here to show, if I can say that, to show them the spirit," Drogba added. "Even if I don't have any doubt about their desire to win, I'm here to help and I will give what I can.

"I'm preparing myself to give something extra to the team and achieve what we want to achieve."

Meanwhile, the 36-year-old Ivorian says that he is looking forward to meeting his former teammate Frank Lampard when Chelsea travel to the Etihad stadium to face Manchester City in the Premier League on Sunday.

The former England midfielder, who joined MLS side New York City FC after being released by Chelsea this summer, is currently on-loan at Manchester City to gain some fitness ahead of the new season in the US.

Although many have criticised Lampard for joining City, Drogba says that the 36-year-old midfielder will also remain a Chelsea legend no matter what team he plays for.

"I can't wait to see him - my partner in crime. It is a pity that I came back and he's not here anymore, but I will be happy to see him," added Drogba. "It doesn't matter the team where he is playing, I think he still belongs to us.

"He is a Chelsea player, for what he did. For me, he is part of the history of the club."