Papelbon can block trades to 17 teams, and Fox Sports' Ken Rosenthal reports that the Brewers are one of the teams on Papelbon's no-trade list.
Papelbon, 34, is expected to make $13 million in 2015 as part of the four-year, $52 million deal he signed in 2011 and can make another $13 million next season if he finishes 48 games this season.
The Phillies are reportedly seeking to dump payroll and also possibly get rid of Papelbon, who was suspended for seven games in September after grabbing his crotch after blowing a save against the Miami Marlins.
He went 2-3 with 2.04 ERA with 39 saves in 43 opportunities last season for Philadelphia, who finished last in the National League East with a 73-89 record.
In nine seasons with the Boston Red Sox and Phillies, the five-time All-Star has a 35-29 record and 325 career saves.
- Scooby Axson