Two sources close to the situation say the deal isn't finalized. Towers, who went 5-10 with a 5.38 ERA for the Blue Jays last season, was non-tendered after the season.
The sources don't consider the deal complete because Towers would need to pass a physical, and some contract language is still being discussed. The sides have discussed a deal under which Towers would earn $400,000 if placed on the 40-man roster, but be paid at a $1.8 million rate if on the 25-man roster. Incentives would start at 35 games pitched.
The Rockies would have Towers compete for a starting rotation spot or operate out of the bullpen. The team has also has re-signed left-hander Mark Redman, who finished 2007 with the Rockies, and right-hander Kip Wells, who pitched for the Cardinals last season.
Towers, who turns 31 on Feb. 26, is 45-55 with a 4.96 ERA in 137 games, including 112 starts, with the Orioles (2001-02) and Blue Jays (2004-07). Towers had 77 strikeouts against 26 walks last season, and had a healthy 1.31 ground-ball/fly-ball ratio.
Thomas Harding is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.