Chris Hernandez, SP
Hernandez has been in Triple-A Pawtucket for a few weeks now, long enough to amass 36 innings. He's jumped his strikeouts up considerably there, which in turn has moved his K/BB to a far more tolerable level. On the other hand, his ground out rate has slipped, and that's what he's going to need a lot of going forward, given he doesn't exactly have strikeout stuff.
Hernandez might be pitching depth for the 2013 Red Sox, given he's ending his current season with the Triple-A PawSox, so it's key that he gets back to what he's good at for the long run. All told, though, he was drafted in 2010, and is already one step away from the majors. That's a pretty good pace to set, and it gives him time to get himself in order before the Red Sox might need his assistance for more than a start or two.
Ivan De Jesus, UT
De Jesus came over in what we will refer to in shorthand as the Nick Punto trade. He's hit like crazy in his (very) short time with Pawtucket, possibly setting himself up for a gig on the 2013 club as a bench player. Even if he doesn't make it there -- between Pedro Ciriaco, and maybe Mike Aviles if he's not the shortstop next year, there are plenty of utility infielders on the major-league roster -- he'll remain on the 40-man roster. A versatile player who might actually hit a bit is a good thing to have around in case someone goes down. And, as Red Sox fans, you know that someone always goes down.
Hazelbaker is in Triple-A after a stretch at Double-A Portland that brought him back from the brink of everyone forgetting he existed. He hit eight homers in a two week stretch, driving his slugging back to a level where he could own a .200 Isolated Power. Now with Pawtucket, it wouldn't be surprising to see him have the same kind of struggles he had when he first got to Double-A. The real question is whether he will rebound and turn into something useful for Boston in the future, or if Pawtucket is going to be the end of the line for him.
For confirmation that Hazelbaker isn't a sure thing, you can check out just about any prospect list. Sox Prospects doesn't list him in Boston's top 20, Kevin Goldstein didn't rank him at all in Baseball Prospectus's top 20, and Baseball America, after ranking him #22 before 2011, didn't list him at all heading into 2012.