The Club is delighted to announce the signing of Tomas Kalas on a season long loan deal from Chelsea.
A centre-back who can also operate on the right, Kalas spent the previous 18 months on loan with Middlesbrough, playing 47 times as they reached the Championship Play-Off Final in 2014/15, before winning promotion as runners-up behind Burnley last season.
The 23-year-old began his career at his hometown club Sigma Olomouc, joining Chelsea for a reported £5.2m in the summer of 2010.
After two seasons on loan at Dutch outfit Vitesse Arnhem, during which time he was named Czech Republic Young Player of the Year, he made his debut for his parent club in a 2-0 League Cup win at Arsenal in October 2013.
His Premier League debut and first start for Chelsea came at Anfield later that season, with Kalas impressing at the heart of defence as the Blues won 2-0.
Ahead of the 2014/15 season he moved on loan to FC Cologne in Germany, but he joined Boro in a similar deal midway through the campaign.
Having represented the Czech Republic at every youth level from Under-17 to Under-21, Kalas also has a number of caps for the senior side, making his debut in November 2012 against local rivals Slovakia.