Seeing Vieira play against Chelsea recently in a match saw a player past his prime. In a preview of what a return would look like, he got decked trying to stop John Obi Mikel. His renowned physical prowess has been undercut by age, few appearances, and frequent injuries since his move to Inter. The Premiership will be even more punishing. Compared to him, we saw a sprightly Gilberto play for Brazil in the Confederations Cup final without suffering any ill effects.
So if Wenger is throwing CW that he never invites back departed players why not go for a Gilberto return? He wanted to stay on at Arsenal until the very end and only reluctantly departed for Panathinaikos. Gilberto might want to come on the same sort of deal.
Having said all of that it would be fantastic to have Vieira back if only for his undoubted leadership skills to a very young Gunners side. His return will remind the side of the halcyon days as one of the key elements of the successful squads of the late 1990's and early 2000s. It is more attractive given that it is a one year contract with a pay for play incentive and wages drastically reduced. He will come to the Emirates for under a million. Plus, the thought of seeing him in a Spurs uniform would be enough to make any red blooded Gunner gag.
Wenger has also undoubtedly been emboldened to taking this step by the Michael Owen move to Man Utd. The Premiership has been blindsided by City and Real's over the top poaching and clubs are replenishing their squads in a variety of different ways. Very young untested talent, aging players or Bosman's. Vieira and Owen are their answers. In Wenger and Sir Alex, they find two managers who are capable of proving these grand experiments a success. In Vieira's case, he comes back to a very promising group of young players, who will look to his competitive nature and strong leadership to stem that swoon the Gunners go through inevitably as the season goes deeper.
As for spending further, Wenger has left the door open but he makes it clear that the squad has what it takes at present.
"I feel we are strong enough but if we can add then we will do it," said Wenger on Arsenal's official website. "In England people think that all the problems can be sorted out by buying players. I believe the biggest target is to work hard in training, improve what we can improve and have confidence in the players that we have.
"If we need to add then we will. We have money available so for us it is now [important] to spend it in the right way when we do it or if we do it."
Vieira's transfer is a tweaking of the intangibles that make a squad stronger.