Michael Ballack believes that Andre Schurrle can become a "main player" for Chelsea in the future following his first season at Stamford Bridge.
The German international moved to the club from Bayer Leverkusen to play under manager Jose Mourinho last year.
"It was his first season playing for a big club and it was a big challenge to go to the Premier League and for that I think he did quite well," Ballack told the London Evening Standard.
"There is still a lot of space to improve - he is still young. Hopefully he can still improve next year and can be a main player for the team."
Chelsea ended the season without silverware and finished the Premier League campaign in third.
