Just so long as we do ot need him to: 1-head the ball 2-use his left foot 3-go past a full back 4-support our full back 5-have any sort of central mid-field playmaker skills Other than that he is warmly welcome
We could use him on transfer deadline day, media clamour round him while we negotiate deals in peace hopefully. Seriously though I'd sign him on a one year deal if he can compete with our other midfielders. The deal should pay for itself considering the marketing opportunities. If he isn't going to have any effect on the field of play though, is no point.
I haven't seen much of Beckham since his move to the US, but he couldn't be accused of not supporting his full-back when he played over here. If we were to sign him, then I'd have thought that one of the few positives would be how much Walker could get out of any potential partnership. He'd have a lot of opportunities to overlap, for a start!