Its not completely impossible, but considering the discrepancy in the team's schedules, it is unrealistic.. Do you really see the Sox playing nine games better than the Rays, if the Sox have to play 30 games against New York/Philadelphia/Tampa(only 11 of which at home)? Throw in a mix of the Rangers/Tigers/Angels/Dodgers, and realize that the Sox have played 8 more home games than away games. I haven't looked at the numbers, but I have noticed the Sox hitting against lefties much better than righties, and well, the only Tampa Bay lefty starting is looking like a Cy Young candidate. So expecting a few big sweeps of Tampa probably won't happen either.
I like this team, I believe in the philosophy the management took at the beginning of the year, and the only thing it actually needs is a new bullpen arm, a new pitching coach and some luck. However, I do not see them getting past the Rays with this schedule, and so many players under performing. After a good start by Lackey, he's starting to look vulnerable, and Dice-k and Beckett switch back and forth between brilliant and looking like they should be playing double A. If just one of Lester/ Buchholz/ Pedroia/ Drew/Papelbon/Bard gets hurt what do you think will happen to this team?
The yankees are so injury-ridden right now that they can be beaten. The Rays are just too good, too young, too healthy with that big hole the team is in already.