He has to hit eighth in the order, the Reds would have to make some other offensive upgrades. Maybe a catcher to go with Hanigan and hit seventh. And a LF. And use the correct players in CF to maximize offense there.
But there's something to be said for keeping Janish as the main shortstop. Perhaps until Cozart is ready. Cozart seems like a similar fielder who may hit more.
With Phillips, Janish, and Rolen, the infield defense is much, much improved. I thought Janish was a bit shaky last year but in 2009 he's been excellent at short IMO. Pretty good range, very surehanded, throws are true.
One way to go is to keep Janish at short and to spend whatever money is available on the outfield. And maybe a pitcher or two to shore up the staff.