The Czech, who has a solitary international cap to his name, spent two seasons on loan at Dutch outfit Vitesse Arnhem before returning to Stamford Bridge for the 2013-14 campaign.
After being handed his Chelsea debut as a late substitute in a 2-0 League Cup win at Arsenal in October, Kalas made his European bow in a last-16 home triumph over Galatasaray.
Kalas' first start for the club came in the huge 2-0 Premier League victory at Liverpool in April, and he was among the starting XI once again on the last day of the Premier League season at relegated Cardiff City.
TOPICS
LATEST ARTICLES
