Tampa Bay is receiving infielder prospect Jadher Areinamo as part of the deal.
Jansen is slashing 204/.314/.389 on the year with 11 home runs and 29 RBI in 73 games. The eight-year veteran will offer some help behind the plate for the Brewers to pair alongside starter William Contreras.
The 21-year-old Areinamo is putting up solid numbers in Single-A+ ball this season, slashing .297/.355/.463 with 11 home runs, 51 RBI, and 15 stolen bases.
Milwaukee is currently tied with the Chicago Cubs for first in the National League Central division with a 62-43 record. Meanwhile, the Tampa Bay Rays are on the outside looking in as they currently have a 53-53 record and are in fourth place in the American League East.