Tomas Kalas
Chelsea defender Tomas Kalas (L) has joined Middlesbrough on loan for the rest of the season Getty

Chelsea have confirmed that defender Tomas Kalas has joined Middlesbrough on loan until the end of the current season.

"Middlesbrough Football Club have completed the loan signing of highly-rated Chelsea defender, Tomas Kalas," a statement on the club's official site read.

The Czech defender, who only recently arrived in England after spending the first half of the season on loan at Bundesliga club FC Cologne, will join fellow Chelsea colleagues Patrick Bamford and Kenneth Omeruo at the Teesside for the rest of the season.

Kalas, who has an international cap for his country has made two senior appearances for the Blues, one of them coming in the 2-0 win over Liverpool last season. He has been impressive when asked to play and has previously spent time on loan at Dutch club Vitesse.

The versatile 21-year-old defender is primarily a centre-back, but can also operate as a right-back and has featured in that position in the past.

It is likely that he will fill in at the full-back position for Middlesbrough as both their right-back's Damia Abella, who was signed from Osasuna in the summer and Ryan Fredericks on loan from Tottenham are out due to injuries, with the former ruled out for the rest of the season with anterior cruciate ligament damage .

Kalas has been training with Aitor Karanka's team at Rockliffe Park and is eligible for selection when Boro visit the Madjeski Stadium to face Reading on Saturday. The Riverside Stadium outfit are currently in fourth place in the Championship just five points behind leaders Bournemouth.