Colon went to the Dominican Republic earlier this week to tend to a personal matter and expressed a preference to stay there, rather than return to the Red Sox and serve as, at most, a long reliever or spot starter for the rest of the regular season.
It's doubtful that Colon -- who made seven starts for the Red Sox -- would have factored into the team's postseason plans.
"He got home for the personal stuff and decided that he just wasn't real comfortable [returning]," said Red Sox manager Terry Francona. "He was either going to be in the bullpen or back up a starter here."
When none of the other 29 teams made a run at Colon over the offseason, the Red Sox took a no-risk flyer on the 2005 American League Cy Young Award winner and signed him to a Minor League deal in February.
Colon suffered an oblique injury in April, but entered the Red Sox rotation for a six-start run on May 21, breaking out to a 3-0 start. But his good fortune ended when Colon tweaked his back while taking a big swing in an Interleague game against the Phillies on June 16.
He finally made it back to Fenway on Sept. 13, earning a no-decision in the second game of a doubleheader against the Blue Jays. Colon went 4-2 with a 3.92 ERA in 2008.
With five able starters healthy (Josh Beckett, Jon Lester, Daisuke Matsuzaka, Tim Wakefield and Paul Byrd), there was not much of a role left for Colon.
By putting him on the suspended list, the Red Sox don't have to pay Colon for the rest of the season.
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.