Stearns had surgery for a hiatal hernia on Feb. 24 after lingering pain in his upper abdomen. He didn't think he would be back with the team until mid-April, and general manager Jack Zduriencik says Stearns will work in the professional scouting department.
"I don't want to be a distraction, and I don't want the players to have to deal with a changeup as their season is starting," Stearns said in a statement Friday.
Donnelly had been hired by Seattle to manage Tacoma of the Triple-A Pacific Coast League. He has coached third base for Pittsburgh (1993-95), Florida (1997-98), Colorado (1999-02), Milwaukee (2003-05) and the Los Angeles Dodgers (2006-07).