Pavlik did not give Martinez a shot, it was TR who picked Martinez for Pavlik as Arum never thought Martinez was going to beat one of his fighters.
Pavlik did not need to fight Martinez when he was not at the top of his game, but he did. And he did not need to take the beating he took when he had nothing left and was blinded by his own blood, Pavlik is a warrior.
Pavlik's biggest weakness is his footwork, like Strike said. He was alright enough against Taylor, but Froch is smarter, fitter and basically a harder man than Jermain was. If Froch isn't strong enough to exchange with Pavlik he's got the option of retreating and making Pavlik press the action. All in all it's not a fight I think Pavlik can realistically win.