There is only 1 answer, and that is TRAVIS WOOD. Of all the non-starters (hitters and pitchers), he's the one most likely to keep the Cubs in the game after an extended relief appearance due to a starter getting shelled, or get out a couple of tough lefties late in the game, or get out of a bases loaded 0 out situation (as he's done before), or come up with a big hit off the bench in extras if all the hitters have been exhausted, or make a run saving catch against the LF wall. Actually, I'd say any of the LHRPs (other than Chapman) have a chance to be an unsung hero. Not sure if Montgomery or Zastryzny will even be on the roster, but both those guys could fill similar roles to Wood. Both can be used to get out a tough lefty (maybe not ideally). Both can be used in long relief in case of a disaster start. Both could be last resort types in extra innings. Both seem athletic enough to give you a couple ABs in LF if the Cubs are facing a team with a tough RHH in between a couple of lefties.