BoxRec

At 168.

12 rounds.

Neutral location.

Prime Calzahge should likely win by a relatively close but fairly clear cut decision but the brittle hands version is probably in for a terribly tough night. I'd actually go with Martinez versus That Version of Calzahge.
As in, a clear cut decision win for Sergio.
He really looked amazing versus Pavlik.

Given that Martínez was a blown-up welterweight and Joe was a 168lb belt-holder for many years, I’d probably go with the bigger fighter by decision. If they had Joe drop to 160 I’d go with Martínez by close decision if the fight was in the US

Sergio just wouldn't be big enough to beat Calzaghe. He's a talented fighter, and he's quick, and he'd make a halfway decent fight of it for a few rounds, but I think Joe's greater strength and relentless workrate would wear Martinez out, and he'd either get stopped or beaten up to a lopsided UD like so many other Calzaghe opponents.