From the Brewers site:
Assuming things progress positively as they have over the last week, it does not look like Sheets will have to start the year on the DL. He is almost certainly a no-go for April 3 against the Pirates, but because of perfectly-placed off-days on April 6 and 11, manager Ned Yost could go with a four-man rotation of Doug Davis, Chris Capuano, Tomo Ohka and Dave Bush for the first two weeks before needing a fifth starter on April 17 at Houston. That could be a reasonable target date for Sheets, assuming he has no more setbacks. Look for Yost to make his plans public in the next few days.
Sheets was bouncing around the clubhouse on Sunday, a good sign that he was thrilled with his bullpen session at rainy Maryvale Baseball Park, and notably snapped off 10-15 curveballs during eight-minutes on the mound. Overcoming the mental hurdle of that pitch -- arguably Sheets' best and the one on which he suffered his original injury last August -- is probably more vital to Sheets' comeback as his physical progress.