This is a rumor of the "Sky Sports understands" variety, so take it with grain of salt. Wes Brown does not exactly make my heart go pitter-patter, but he's a solid and somewhat versatile defender, capable of playing in the middle or at right back. Brown's 15 years with Manchester United are pretty clearly coming to an end given his desire for first-team football combined with the existence of Rio Ferdinand and Nemanja Vidic. The 31-year-old former England international would likely be an upgrade over Richard Dunne, but not enough of one to justify any sort of bank-breaking. A million or two? Certainly. But nothing more than that.
Before the club goes making any moves for central defenders however, I'd prefer to see how Dunne looks in training and playing in McLeish's system. This is a player that was the club's 2009-10 Player of the Season after all, and while he looked poor from the get-go last season he was also battling injuries well into Gerard Houllier's time in charge. The former manager called for a far higher defensive line and ball-playing from his center backs than McLeish likely will, and it's quite possible that in a different tactical system that Dunne can once again be an above-average player. It's also possible that Brown is being looked at primarily as a right-back (assuming he's actually being looked at in the first place) and if that's the case, well, we should probably just go ahead and sell Carlos Cuellar back to Rangers. But that seems something of a long shot.
I'd strongly prefer Aston Villa get things sorted at positions of actual need (such as both left and right back) before shoring up depth elsewhere, but Brown isn't a bad player to have in a side. This is pure conjecture on my part, but it wouldn't surprise me if he's a part of Ashley Young's move to Old Trafford, and if that ends up being the case then I'll be strongly in favor. But it's also Sky Sports, so the entire thing is probably a complete load of wank.