Arsene Wenger
Arsene Wenger has begun his summer activity by signing Granit Xhaka from Borussia MonchengladbachGetty

Former Arsenal striker John Hartson believes the Gunners are in for a busy summer with Arsene Wenger set to splash the cash for the first time during his reign at the club. The French manager has begun early by wrapping up the signing of Granit Xhaka before the start of the European Championships, which begin in France on 10 June.

According to the Daily Mail, the north London club have paid Borussia Monchengladbach a fee of around £35m ($51m) to bring the midfielder to the Emirates Stadium in the summer, making him Arsenal's third most expensive signing after Mesut Ozil and Alexis Sanchez. He is likely to continue reinforcing the team after admitting that he will also sign a striker following Danny Welbeck's injury –which will keep out for at least nine months.

Hartson, who made 54 appearances for the Gunners between 1995-97, feels Wenger is going to finally make use of the transfer funds at his disposal, especially as it could be his final season at the club as the Frenchman's contract comes to an end next summer. The former Celtic striker, however, has called on Wenger to spend big on a marquee signing – like Robert Lewandowski to complement the existing marquee players in the squad.

"I do think Arsene Wenger will spend an awful lot of money this summer. He'll spend big and with him having probably just another year there, he'll think 'right, I'm going to go out with a big bang'," Hartson said, as quoted by the London Evening Standard.

"I reckon he'll think 'I'm going to spend all this money that's been given to me'. I think he'll actually spend up to £150m this summer, I really, really do."

"I'd like them to go and get a Lewandowski, that type of player. Someone like how [Thierry] Henry was. Someone who is mobile, someone who is a real presence, someone who can head it, score left foot, right foot and fire in volleys. I think the crowd would love that too.

"Alexis Sanchez has flattered to deceive at times this season even if he did have a wonderful first year. Now another big marquee signing is needed. I know they've got in Ozil and Sanchez and paid big money for them, but I'd love a Lewandowski."