"Four innings, one hit, ended up throwing 48 pitches," Melvin said."[Alvarez] even mixed in a couple of his curveballs, I've been told. So that means he's feeling pretty good. All good there."
Alvarez is expected to have about a 75-pitch limit in his next rehab start.
"We're getting him to the point that we're starting to get excited about it," Melvin said. "… At this point, knock on wood, there haven't been any setbacks. Once you get him up to the 90-pitch mark or so, you're close to getting him back."
Alvarez was signed by the A's to a one-year deal this offseason. He was an All-Star with Miami in 2014.
Willie Bans is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.