AITOR KARANKA thinks he has finally proven there was more to Middlesbrough's winning habit either side of the New Year than just the luck of the hamster.

Boro took 16 points from a possible 18 over the festive period and that coincided with the arrival of Holly the hamster.

Prior to Holly's introduction – as part of the squad's secret Santa gift giving to each other – Middlesbrough had also seen remarkable improvements defensively following the acquisition of Shay Given on loan from Aston Villa.

Many feared Given's return to Villa in February would have sparked a downturn in the team's defensive performances. However, that has not been the case.

Karanka, ahead of today's visit of Millwall to the Riverside, thinks the fact Middlesbrough have conceded fewer goals (20) than any other side in the Championship since he took over in November indicates his methods are not just the result of a few individual decisions.

“When we were winning people said it was the luck of the hamster, then it was because we had Dean Whitehead in the team and before those it was Shay Given,” said Karanka. “Maybe I would like to have the hamster, Dean and Shay and we will win every week (laughs).

“What is more important than those is for all of the players to know who can play where and for them to stay in the team by doing the work what is expected of them and what I demand from them.

“Since I arrived all of them have done the things I have wanted. They have all understood what I have wanted and you can see that in the performances.”

One of the most surprising things about Middlesbrough's record under Karanka has been the way the team have continued to prevent teams from scoring too many against them despite regularly changing the backline.

He has already used four goalkeepers during his six months in charge, while he has been forced to use many different defensive line-ups, which included a wing-back system at Burnley last weekend.

Against Millwall today there will be further adjustments because George Friend is available again after a groin injury and Kenneth Omeruo is likely to replace the suspended Daniel Ayala.

Karanka said: “When I need to change the defenders every week, they all play well and it shows they understand my work. The most important thing for me is that they do it on the pitch.

“It is important they get their shape with or without the normal right back or left back. It is just the work of a manager to acknowledge your players’ strengths and weaknesses and that is what I have done.

“When I was putting Jozsef Varga at right-back everyone said I was crazy. I knew I wasn’t because I had seen the players train every day. I know where the players can play.

“I know who are the best defenders, but the players who play will be the ones I think suit the team. If somebody is not training well, like my first central defender, then he will not play. This is my philosophy and I will not change that.”