Mike Evans vs. William Gay
Ike Taylor is absent for the Pittsburgh Steelers, which means the Bucs have to go after his replacement: William Gay. The Steelers defense as a whole is fairly vulnerable, but having to do without their top (albeit old) cornerback presents the Bucs with a real opportunity to pick on a weak secondary.
Of course to do so, they first have to throw the ball to Mike Evans, who's most likely to take on Gay. And they'll have to do so by challenging him down the field, not just on the short passes the Bucs have mostly thrown this season. Mike Glennon will have to feel comfortable and be decisive with his throws, while the offensive line will have to give him enough to be those things.
The offensive line vs. zone blitzes
If there's one thing the Pittsburgh Steelers can do well and will always do well as long as they have Dick Lebeau as their defensive coordinator, it's blitz. They do so with overload blitzes, with zone blitzes, with movement and without in any number of ways. And all of that is bound to cause issues for a Bucs offensive line which is still learning how to communicate with each other.
That's going to be a problem, both in the pass game and in the run game. The Pittsburgh defensive line is injured and not all that great to begin with, but if they can unsettle the Bucs' line with movement they should still be disruptive. And the Bucs can't have that.
Austin Seferian-Jenkins vs Troy Polamalu
Actually, I'm not all that certain who Seferian-Jenkins will end up facing the most: it might be Polamalu, but it could also be Jason Worilds, or Lawrence Timmons, or Ryan Shazier. And he'll likely face each of those at various points during the game.
Seferian-Jenkins is going to be an offensive key to the game regardless of who he'll go up against. Brandon Myers hasn't been bad, but he's not much more than a serviceable check-down option as a receiver, while his blocking is nothing special either. Seferian-Jenkins can be explosive and a quality blocker, which is the kind of flexibility the Bucs offense could build around.
Assuming he's healthy on Sunday, and it does look like that, I'd look for heavy involvement from the rookie tight end in both the run and pass game. And that could make all the difference in the outcome of the game.