HE has been involved in Champions League finals and La Liga title deciders during his time as assistant manager at Real Madrid, but as he prepares to lead Middlesbrough into the first leg of their play-off semi-final at Brentford tonight, Aitor Karanka admits he is embarking on the biggest week of his career.

Boro kick off their play-off campaign at Griffin Park, with the second leg due to take place at the Riverside in seven days time, and having missed out on automatic promotion in agonising fashion in the closing two weeks of the season, Karanka opted to take his squad to Spain for a four-day training break in the build up to the game.

The Spaniard has been delighted with his players’ response to the change of scenery, and is confident any lingering disappointment at failing to make the top two has completely disappeared.

The stakes could hardly be higher as Boro prepare to tackle the play-offs for the first time since dropping out of the Premier League six years ago, and while he has plenty of experience of big occasions as the number two to Jose Mourinho, even Karanka concedes that the pressures of the play-offs represent something new.

“Of course, this is the biggest game of my life so far,” said the Boro head coach. “I don’t have any doubts about that. It is the first time that a team of mine is going to be playing for something.

“I have been here 18 months now, but the first season was just about saving the team (from relegation) and nothing really happened at the end of the season. This season, we were fighting for something until the very last second, and now we get the chance to play in the play-offs.

“For me, it is a very important challenge because I have never been in a situation like this. I have experience of big games as a player, and alongside Jose, and all of those situations are different.

“I hope I am ready, and the players know how important this is too. They know it is a very good opportunity for them, but I don’t want to put any extra pressure on them because they already know how important it is for everybody.”

Boro’s major selection dilemma ahead of tonight’s game relates to Patrick Bamford, with the Championship Player of the Year not having taken part in a full training session for a fortnight now because of an ongoing ankle injury.

Karanka will not make a final decision over the striker until later today, but with the second leg to consider as well as tonight’s game, he will not be taking any unnecessary risks with Jelle Vossen and Kike available as alternatives.

“I hope he will make it, although he hasn’t been able to train,” said Karanka, who has allowed Dwight Tiendalli to cut short his own loan spell and return to Swansea City. “I won’t be taking a risk because there are two games and if Patrick plays in the first one, it will be because he is ready to play.

“After the game against Brighton, I thought he would be much better this week than he has been. Sometimes, you think injuries will be over after a week, but they take more. For that reason, I cannot take any risks, so we will have to see how he is in the build up to the game.”

Bamford’s long-term future remains the subject of considerable conjecture, with a host of top-flight clubs queuing up to express an interest, and while Karanka would dearly love to have the 21-year-old back at the Riverside next season, he accepts Boro’s chances of another loan deal will be determined by whether or not they win promotion.

“I would like to keep him because he is the top scorer this season and, for everybody, it was a very good decision for him to come here. He has improved a lot, and the players are very happy with him.

“Chelsea are happy because he is a better player now, and of course I would like to keep him with us, but the most important thing for that is that we are in the Premier League.

“Patrick has shown this season that he is a Premier League player and, for that reason, if we are not in the Premier League, I think he will have other chances to play in that division. But we have to think first about this game and then the game on the following Friday. That is the focus.”

The play-offs are slightly unusual in that the away goals rule does not apply, so while it would clearly be preferable for Boro to be taking a first-leg advantage back to the North-East, there is more of a focus on defensive security this evening than on all-out attacking in search of an away goal.

“It is different to games I have been involved in Spain,” said Karanka. “In them, if you draw the first game 1-1 away and then draw 0-0 at home, it is enough. So in Spain, you can get to the final without winning a game.

“Here, you have to win a game, so it is different. In the Champions League, it is very important to score a goal away, but here if you score one goal but concede two or three, you are not in a good position.

“It is different, but I have been thinking about that ahead of the first game, and then after that, we will prepare for the game in Middlesbrough.”