MARYVALE, AZ (WHBL) - Milwaukee Brewers' right-fielder Corey Hart will be out for 3 to 4 weeks with a torn meniscus in his right knee.  An M-R-I disclosed the injury Sunday morning.  Hart will need surgery and it's not known whether he can return in time for the Brewers' regular season opener against Saint Louis on April sixth.  Assistant general manager Gord Ash said Hart has had a history of meniscus problems but never at this level.  It's the second spring in a row that the All-Star Hart has had injury problems.  He started last season on the disabled list with a strained rib cage.  Also, Brewers second baseman Rickie Weeks has a stiff right throwing shoulder, and he's considered day-to-day.  Ash said the shoulder been bothering him for some time.  Weeks sat down after he took some throwing drills yesterday morning.  Brewers' manager Ron Roenicke also said pitcher Mark Rogers strained his left hamstring while backing up home on a play during the team's intra-squad game on Saturday.  He's expected to miss a couple days.