The 20-year-old Czech has made just one brief substitute appearance, in a Capital One Cup tie last October, since joining the club from Sigma Olomouc in 2010.
Two season-long loan spells with Vitesse Arnhem in the Dutch Eredivisie followed an initial loan back to Sigma, but despite his current contract lasting until 2017, Kalas has admitted that some kind of move away from Chelsea may be his best option for his goal of playing regular football.
"I would go anywhere where it would give me what I want to keep improving," he said.
"The main thing is to be playing regularly. I'm not saying to be an automatic starter, I will be happy to fight for my position bit I want a more realistic chance to play than I have here.
"The English leagues are known for being physical and fast, so maybe it would be good to stay here. The best scenario would be if I could stay in my current home but it's not a condition.
"In the Championship it's good that there are even more fixtures, but we will meet with the management and see what's next."