Chelsea have confirmed this morning that Tomas Kalas will be spending the 2014/15 season away from Stamford Bridge. He'll be joining FC Cologne, who were promoted to the top flight in Germany this spring.
Kalas had two previous spells on loan, both spent in the Eredivisie. He played primarily as a center back for Vitesse Arnhem during the 2011/12 season, before taking over as their first choice at right back during 2012/13. He then spent last season under Jose Mourinho, where he made a few impressive appearances toward the end of the season at center back. He's expected to continue in the middle of the defense at Cologne.
For Kalas, this is probably a perfect destination based on where he's currently at development-wise. The Bundesliga isn't as good top to bottom as the Premier League, but it's still a massive step up in class from what he faced in the Netherlands. That said, Cologne will likely be terrible, and Kalas will probably spend the vast majority of his time in Germany with his opponents in possession. Sounds like fun.