There are lots of guys on the team hitting better than that. I'm sure Dukes has more to contribute, but hitting .215 in AA ball doesn't exactly scream "bring me up!"
They should cut Mackowiak and bring up Langerhans now. Langerhans is a gifted fielder, and it seems he's solved his hitting problems. Not that Lenny can't screw him up again, but he's hot now, get him up here.