Sherrill, 34, had some minor discomfort while throwing before pitchers and catchers reported on Feb. 11, and the Mariners chose to just delay his start in order to avoid any problems.
"It felt pretty good," Sherrill said. "I'll play catch [on Wednesday], and see how it bounces back."
Sherrill signed a one-year, $1.1 million deal as a free agent to return to the Mariners. He pitched in Seattle from 2005-07, before getting traded to the Orioles and becoming an American League All-Star in 2008.
He pitched for the Braves last year, posting a 3.00 ERA and 3-1 record in 51 appearances, and is expected to be the Mariners' situational left-hander, if all goes according to plan.
The Mariners will hold the first of three planned intrasquad games on Friday, but pitching coach Carl Willis said he wasn't ready to disclose which pitchers will throw just yet. Sherrill is the only pitcher who hasn't been a full go thus far, however.