I think that is one of the big questions the Tigers must decide with their postseason roster.
On the surface, Penny seems to be the better candidate. Certainly he has more experience. Tiger fans curent dismay with Penny aside, I see him as a better option than Below to start a postseason game - if necessary.
But Below may have more value as a reliever. He is left-handed. He has pitched in that role reasonably effectively this season. I don't necessarily see Penny adjusting to a relief role.
Penny has only made four relief appearances in the regular season during his entire major league career - and has an 18.00 ERA as a reliever.
Half his eight appearances in the postseason have been in relief. He is 1-1 with a 3.85 ERA as a reliever in the postseason. But he hasn't pitched at all in relief since 2008.
Below has done OK in relief for the Tigers - a 1.186 WHP and a 3.86 ERA.
A lot will depend on manager Jim Leyland's willingness or hesitation to pitch his starters - particularly Justin Verlander - on a shorter rest, if necessary, during the postseason.
Also, Below has rarely pitched in a victory. For the most part, he's mostly done mopup work for the Tigers.
Could neither be on the postseason roster? That will be another interesting call that could involve Carlos Guillen.