Gilberto Silva fears for Arsenal once Arsene Wenger chooses to step away.

Gilberto suggested Arsenal supporters might be in for a shock once Wenger departs, claiming they only need to look at United's demise after Sir Alex Ferguson's retirement.

"Arsene at this time is facing a lot of criticism for the way the team play and they haven't got the trophies," Silva told the Daily Mail.

"But if people see the entire job he has done for the club, it has been amazing. I hope people do realise that, because when he leaves the club at some point it won't be so easy to replace him.

"You can see, for example, at Manchester United where it's not been so easy to replace Sir Alex Ferguson. It's important for Arsene and for the club to start to prepare somebody for when he leaves.

"I don't know if it will be this season as his contract is expiring. He loves the game, he loves what he does and he loves the club."