The Twins will open another roster spot Wednesday by allowing righthanded reliever Michael Tonkin to sign a contract with the Hokkaido Nippon Ham Fighters in Japan, a major league source confirmed Tuesday.

Tonkin, who turns 28 later this month, posted a 4.43 ERA in 141 appearances over parts of the past five seasons with the Twins, but he never was able to claim an end-of-game role he was groomed for in the minors, where he racked up 65 career saves. His fastball regularly exceeds 95 mph, however, making him particularly enticing to Japanese teams.