Baseball America has a nice (free!) article on the big five anchoring the pitching staff at the Cubs' AA club:

"We've got a good mix," [pitching coach Alan] Dunn said. "We've got power guys like Brownlie and Blasko, although they are different types of pitchers. But they will both light up radar guns for you. Then you've got Nolasco, who's more of a Mitre type. When he's effective, he's not going to blow you away with power stuff, but he's got a good fastball when he keeps it down in the zone. He's also got a put-away pitch in his overhand curveball."

The other two guys in the starting rotation are Carmen Pignatello and Renyel Pinto.