Saints last night made their first signing of the summer, completing the £8.5m capture of Lyon's highly-rated centre half Dejan Lovren.

The Croatian international, 23, has signed a four-year contract at St Mary’s after moving from the French club.

Lovren, who was linked with a move to the club earlier this week, bolsters the heart of the Saints defence – an area that had been identified as a key priority for improvement this off-season.

Lovren, who said he hopes to stay at Saints for a “long time”, told the club’s official website: “I’ve spoken a lot with the chairman and the coach, and this is a great project.

“They told me a lot of positive things, and I know the history of the club. It’s a big club and I’m very happy that I can be a part of it.

“After three-and-a-half years in France, it was a dream to play in the Premier League. Now the dream has come true.

"I have it in my mind to do something big, and I see the same thing in the club.”

Lovren joins Maya Yoshida, Jose Fonte and Jos Hooiveld, as well as Vegard Forren, in the first-team centre half ranks.

As previously reported, that was a position that Saints were determined to strengthen this summer.

The club have an ambitious recruitment drive planned, and are also understood to be targeting a new central midfielder, striker, wide player and right-back.

They have also scouted keepers and left-backs, but those positions are not such priorities, although the market will no doubt be monitored in case an attractive opportunity presents itself.

Speaking about the addition of Lovren, Saints boss Mauricio Pochettino said on the club’s website: “We are very happy because Dejan is a very good player with good potential.”

Lovren joined Lyon in 2010 from Dinamo Zagreb, in an €8m deal, spending three-and-a-half good years with the French side. He has been capped by his country 17 times.