Middlesbrough Football Club have completed the loan signing of highly-rated Chelsea defender, Tomas Kalas.

Kalas will arrive on a loan deal that could keep him on Teesside until the end of the season after returning to England from a loan spell with German side FC Koln.

A Czech international, Kalas has made two appearances for Chelsea and has had a previous loan spell with Vitesse in the Dutch Eredivisie.

The versatile 21-year-old can play at either right-back or centre-back and will be a solid edition to Aitor Karanka's squad after a season that has so far been blighted with injuries.

Damia Abella was signed from Osasuna in the summer to play at right-back, but the Spaniard suffered anterior cruciate ligament damage and has been ruled out for the rest of the season.

Fellow right back Ryan Fredericks, on loan from Tottenham Hotspur, is also currently sidelined with injury.

Kalas, who joins fellow Chelsea loan men Patrick Bamford and Kenneth Omeruo, has been training with Aitor Karanka's squad at Rockliffe Park and will be available for selection for Boro's game against Reading at the Madejski Stadium on Saturday (3pm).