Lamb began last season in Minnesota but was waived by the Twins and signed with Milwaukee on Sept. 5. He hit .273 in 11 games for the Brewers.
His deal with Milwaukee is for the $400,000 minimum, which will be offset against the $3 million salary he was guaranteed from the Twins under a $6.6 million, two-year deal.
Milwaukee also agreed to a one-year deal with right-handed reliever Todd Coffey, avoiding arbitration. He can earn an additional $200,000 in performance bonuses: $25,000 each for 20, 30, 40 and 50 games, and $50,000 each for 60 and 70 games.