Usually when a player goes on the DL retroactively, it's in the interest of getting him off the DL fairly soon. But this doesn't sound like that, since torn rotator cuffs usually result in surgeries and extensive time out. Narveson's shoulder injury comes right on the heels of a hip injury that required off-season surgery and kept him on crutches for six weeks last winter.
There's no word yet on Narveson's replacement, but swingman Marco Estrada posted a 3.70 ERA with fine command in seven starts for the Brewers last season, and seems likely to be first into the breach.
Milwaukee, regarded before this season as strong contenders in the National League Central, enters this weekend with a 6-7 record and a 5.05 team ERA that ranks last in the league.
Update: It's official - Estrada's starting in place of Narveson, Saturday against the Rockies.