Suppan, who helped the St Louis Cardinals to the World Series in October, winning the National League Championship Series MVP honours, is scheduled to undergo a physical next week.
"We're jumping the gun a little bit, but we wanted to make an announcement before things leaked out," Brewers general manager Doug Melvin said. "There was some momentum to this, so we kept going with it."
Suppan has been a work horse throughout his 12-year career, which included stints in Boston, Arizona, Kansas City, Pittsburgh and St Louis, making at least 31 regular-season starts in each of his last eight seasons.
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He has compiled a record of 106-101 with a 4.60 ERA in 317 games.
Last season Suppan posted a record of 12-7 with a 4.12 ERA and is 5-2 with a 3.00 ERA in nine playoff starts.
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