Pivetta just seems better suited to a RP role, he can use two pitches, throw harder and seems to get pumped up.
Myers made the transition pretty well, and Madsen is the poster boy for a below average SP who became an above average RP.
Think Velasquez would be well suited to the pen as well where he can maintain his explosive FB and just focus on one secondary pitch, but don't like Eflin or Eickhoff in the role.
Eflin has the velocity, but he's more of a soft contact pitcher who can go deep into games if his stuff is right.
Might have been Nola's best game, used the 2 seamer and the changeup more, and they were difference makers, for some reason he's throwing more 4 seamers and not using that nasty 2 seamer to freeze hitters. And the changeup keeps hitters from looking for the curve.