PHOENIX -- Rockies right-hander Jhoulys Chacin threw a 40-pitch bullpen session on Saturday -- the first big test since he suffered a back strain on April 19 and landed on the disabled list.
Chacin will throw either in an extended spring game or Minor League game Tuesday, with a goal of returning to the rotation against the Rays at Coors Field on May 5.
In four starts, Chacin is 3-0 with a 1.46 ERA, with 16 strikeouts against six walks.
"Right now, I think he's the best starter in the National League, and we need him back," Rockies catcher Wilin Rosario said. "I ask him every day how he's feeling, because we want that guy on the mound."
Thomas Harding is a reporter for MLB.com. Read his blog, Hardball in the Rockies, and follow him on Twitter @harding_at_mlb. This story was not subject to the approval of Major League Baseball or its clubs.