"It felt good yesterday," he said Monday before heading out with trainer Rick Griffin for his follow-up. "Now I've just got to go run and test it again."
Manager Eric Wedge said things are progressing as needed.
"He's still lined up for Tuesday," Wedge said. "We anticipate everything being fine and he'll be good to go."
The biggest test was the bullpen session.
"It went pretty good," Wedge said. "You don't want to go too far with it, but he had a good work day and was even getting off the mound and fielding some bunts and things. So it was a pretty good test yesterday."
Harang is 1-4 with a 7.30 ERA in five games since being acquired by trade from the Rockies on April 12. He began slowly after not pitching for several weeks, but had back-to-back quality starts before his Thursday outing against the Yankees was scratched.
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.