Agree that Maxwell has potential to put up "younger Carlos Pena" numbers of .235 with 30 HR and 85 RBI if given a full season's worth of at-bats. Unfortunately that comes along with 175+ K, but not the 80+ BB or .350 OBP that Pena typically manages.
 
For breakout player I'm thinking maybe Matt Dominguez. Based on the final 30 games of the season last year, where he hit .284 with 5 HR, and 45 games at OKC hitting .298, I don't think it would be completely unreasonable to see him hitting .265 with 18 HR if he's our everyday third baseman.