The amount received for Mastny was not disclosed.
This development was a Mastny-initiated move. His agent approached the Indians and requested that they agree to the swap because he can make a minimum of $800,000 as a starter in Japan in 2009, with potential incentives pushing that number even higher. Mastny's deal with the BayStars also includes an option for 2010.
While the Indians certainly have a need for depth in their bullpen, they felt they were doing the right thing by allowing the right-hander to pursue this opportunity.
"It's the best thing for Tom," Shapiro said. "He's a guy we have a lot of respect for. It was a question of whether it was in our best business interest. But we're sensitive to and understand this juncture in his career and what this means for him and his family. He's a 28-year-old guy with a newborn baby."
The Indians are not ruling out the possibility that Mastny could rejoin the organization in two years.
Mastny had been in the Indians system since he was acquired in the trade that sent infielder John McDonald to the Blue Jays after the 2004 season. He made his big league debut in 2006 and spent some time in the closer's role at the tail end of the season, saving five games
The right-handed Mastny spent the full 2007 season in the Majors, going 7-2 with a 4.68 ERA in 51 outings. His highlight with the Indians came in Game 2 of the American League Championship Series in Boston, when he came on in relief in extra innings and recorded the victory.
In '08, Mastny did not win a job with the Tribe out of Spring Training. He began the season in Triple-A Buffalo and was called up four different times. In all, he went 2-2 with a 10.80 ERA in 14 appearances with the Indians and 2-2 with a 1.78 ERA in 28 appearances for the Bisons.
With Mastny out of the picture, the Indians' 40-man roster now stands at 38 players.
Anthony Castrovince is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.