Zack Gelof (knee) will begin a rehab assignment with Triple-A Las Vegas on Tuesday.
Gelof has been out since July 9th after cutting his knee on the outfield fence while making a sliding catch. He began baseball activities a little over a week ago and is closing in on a return. He will likely need at least a week of games to get his timing back, but he could return to the Athletics’ lineup by the middle of August.