Middlesbrough manager Aitor Karanka says the door is "always open" for Chelsea striker Patrick Bamford to return to the club.Bamford, 22, joined Crystal Palace on a season-long loan during the summer transfer window but has not started a single Premier League game for the club. In all competitions, he has been limited to just 181 minutes of playing time and has described his season as "frustrating" and "upsetting".

Palace boss Alan Pardew admitted in October the club would review Bamford's situation before January, with the possibility of the striker returning to Stamford Bridge before leaving to join another team on loan now looking increasingly likely.

Bamford rose to prominence at Middlesbrough last season, scoring 17 goals for the club and winning the Championship Player of the Year award. Should the opportunity to take him back for the second half of the 2015-16 season emerge, Karanka says his side will welcome the player with open arms.

"I think it's understandable that he is linked with us because he was really successful last season here," Karanka was quoted as saying by Gazette Live. "Everybody has a good relationship with him at this club. I have always said the door is open to him, I have a good relationship with him and we will try to make the best decision for everybody."

Bamford's only starts for Palace this season have come in the League Cup in ties against Shrewsbury Town and Manchester City. Despite that, Pardew has spoken enthusiastically over the England Under-21 international's potential, believing he will go onto represent his country at senior level.

"Hopefully when he hits the ground at some point, whether it's for us, Chelsea or somebody else, he's going to feel the benefit of it," Pardew told a press conference in October. "He is, in my opinion, a possible England player at some stage but he has got some learning to do."