After legging out the game winning run, everyone was surprised that Salty made it safely. Tek thinks that "He runs real well for a big man", and compared to Varitek, he is lightning quick.
Running real well for a big man is not saying much. It's just a nicer way of saying "He's slow, but compared to all the big men, he is the fastest of the slow group".
No matter the speed, he was the only guy available, and it worked out. Kudos to Tito.