Chacon, 31, last pitched for the Newark Bears of the independent league, with whom he posted a 4.29 ERA in seven starts. The eight-year Major Leaguer was assigned to Triple-A Sacramento and is scheduled to start for the River Cats on Friday, The Denver Post said while confirming the signing.
Chacon, a third-round Draft pick by the Rockies in 1996, went 22-29 with a 5.10 in his first three years in Colorado and was named an All-Star in 2003. His best statistical season came in '05, when he went 8-10 with a 3.44 ERA with the Rockies and Yankees.
In '07, Chacon -- mostly a starter up until that point -- posted a 3.94 ERA while making 60 of his 64 appearances out of the Pirates' bullpen.
The following season, he made 15 starts for the Astros but was released after an altercation with general manager Ed Wade. Chacon ended up being suspended for insubordination and then being placed on waivers after he and Wade engaged in a confrontation on June 26 that ended with Chacon throwing Wade to the ground.
Chacon moved to the independent league this season and has held his opponents to a .253 batting average.
Alden Gonzalez is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.