AITOR KARANKA will run the rule over some potential left-back signings ahead of the January transfer window after admitting that Ben Gibson is not naturally suited to the role.

Gibson filled the left-back slot in Saturday’s 2-2 draw with Birmingham in the absence of the injured George Friend, and will remain in the same position when Brighton visit the Riverside this weekend.

Friend is expected to be absent for at least another fortnight with a knee injury, and his absence has highlighted a lack of alternatives on the left-hand side of the Boro back four.

Gibson spent some of his youth days playing at left-back, but the 20-year-old has developed into a centre-half in the last couple of seasons and reverting to full-back no longer plays to his strengths.

Similarly, while Andy Halliday has appeared at left-back in the past, the Scotsman is really a winger and the defensive side of his game will need major improvements if he is to spend a lengthy period in the back four.

With the Football League loan window closed, Boro are unable to make any alterations until the industry-wide transfer window opens at the start of January.

However, Karanka is already assessing his options and is understood to have instructed his recruitment team to assess some potential left-back additions.

“I hope he (Friend) is back as soon as possible because Gibson is not a left-back,” said the Boro boss. “I hope George will be with us in two weeks maybe. The problem is in his knee.”

Friend’s injury has deprived Middlesbrough of one of their more experienced players, and the concession of costly late goals against Derby and Birmingham last week suggests the club is suffering from a lack of leaders.

Twice in the space of four days, the Teessiders were unable to shut up shop late on, a failure that effectively saw them throw away three points.

Given they are only four points clear of the relegation zone, they can hardly afford to be so profligate, but Karanka denies that his side is suffering from a lack of leadership qualities.

“We have Woody (Jonathan Woodgate), (Daniel) Ayala, Grant (Leadbitter) and Dean (Whitehead),” he said. “We have plenty of players that can lead us – it’s just silly mistakes.

“When it comes to our defence, I am very happy with them 95 per cent, but there is five per cent where we need to improve.

“Daniel played a very good game (at Birmingham), and while Gibson gave away the penalty, he played well. Rhys (Williams) and Woody were the same. When we concede two goals, it’s not always on the defenders - it’s on the other players too.”