The deal is pending a physical, according to the report.
The Twins cut Plouffe in November, after which he cleared waivers and elected to become a free agent.
The 30-year-old was a first-round draft pick of the Twins in 2004. After struggling to earn a spot as a shortstop, he turned himself into a reliable third baseman with solid power.
Plouffe, limited to 84 games last season because of injuries, batted .260 with 12 homers and 47 RBIs. In seven seasons with the Twins, he hit .247 with 96 home runs and 357 RBIs.
Information from The Associated Press was used in this report.