HE has already identified a number of reasons behind Middlesbrough's downfall last season, but manager Tony Mowbray has revealed the lack of core players is a major problem that he is desperate to change.

Mowbray's search for summer reinforcements is already underway and the Boro boss has already taken in several games both at home and abroad since the Championship season finished at the end of April.

He is wading through a list of potential signings that have been recommended by his scouting team and is hoping to get the bulk of his summer business done before his squad return to training on June 24.

In the final weeks of the season, Mowbray was continually asked why his side had failed to maintain a top six position despite entering 2013 third in the table.

The Boro boss admitted it was a culmination of several different factors, including a constantly busy treatment room and poor away form, but he also feels the core of his starting XI wasn't strong enough to get Boro through some games.

Goalkeeper Jason Steele was the only ever-present player throughout the season and Mowbray admits that statistic is something he needs when the new season gets under way in August.

"We haven't had a stable core of the squad," he said. "We've maybe had Steele, Leadbitter and Hoyte until Christmas, but we haven't had a core of six, seven, eight players that I could pick every week.

"I don't think we had many at all. It's been a frustration and I think we need to have players that get picked every week not because we have to pick them every week, but because they're good enough to be picked every week and their performance level is consistent to be picked every week.

"As a football manager if you have a team that picks itself every week and has the same energy levels, quality and productivity you keep picking it."

And Mowbray, who has pinpointed the areas he needs to strengthen, has highlighted the need to bring in versatile players capable of filling in different positions across the field.

He said: "Ideally you have the versatility of players to play the same team but with different shapes and formations, because top players can play everywhere really as some of ours have had to. If you're a centre midfield player and you have to play on the right, you can do it without many problems.

"In an ideal world you've got a few players in your squad that are versatile enough, otherwise you'd have to have two players in each position."

Meanwhile, three Boro youngsters have been named in the England U16 squad for this summer's Nordic Tournament in Norway.

Callum Cooke, Matthew Elsdon and Jonathan Helm are all called up, while Lewis Scoble has been placed on standby.

The annual tournament takes place in Oslo from August 1 to 11.

Meanwhile, Ryan Brobbel has been selected for Northern Ireland U21s' European qualifier against Cyprus in Nicosia on Thursday, May 30.

ENDS