AITOR KARANKA believes the core of a successful Middlesbrough side is already established, and will be looking to make targeted improvements in key areas this summer rather than attempting a radical overhaul of last season’s squad.

The Teessiders finished the campaign in mid-table, but their form under Karanka would have taken them to the fringe of the play-offs had it been replicated over the whole of the campaign.

After replacing Tony Mowbray last November, Karanka set about making his side more defensively secure and difficult to break down, and the results were clear to see as they recorded a succession of clean sheets in the second half of the campaign.

A lengthy run without a goal highlighted problems at the other end of the field, and adding a new centre-forward will be a priority this summer along with the recruitment of a new right-back to replace Stuart Parnaby and Frazer Richardson, who were both released last week.

It is anticipated that three or four new players will arrive at the Riverside this summer, but while the final figure will be dependent on what happens to Marvin Emnes and Lukas Jutkiewicz, who are wanted by Swansea City and Bolton Wanderers respectively, there will not be a wholesale restructuring of the squad.

“The basis of the team is built,” said Karanka. “We had 15 clean sheets (last) season, so you can see that the basis of a successful team is there.

“Now, we have to address the positions where we have had problems, and that is at right-back and with the strikers.”

Karanka is determined to retain his most influential players from last season, and is expected to rebuff interest in Grant Leadbitter from a number of Championship clubs.

However, the Spaniard accepts that Boro will always be vulnerable to losing their leading assets if top-flight clubs come calling.

“If good teams want our players then that is a good thing because it proves that we are working well,” said Karanka. “If that happens, then we would have to make a decision on a case-by-case basis.

“The most important thing is always the team, and what works best for the club as a whole. But if a Premier League club was to come to sign a player, I might say, ‘No, I want this player here’, but the player might want to go.

“That would potentially change things. Now, and in the future, I want players in my squad who really want to be here playing for Middlesbrough.”