Jaso is hoping to pick right where he left off before the injury, having hit .349 in June after combining for a .252 clip in April and May.
His return also means the A's, now equipped with three healthy catchers, will likely feel comfortable sending one of them -- likely Stephen Vogt -- back down to Sacramento on Thursday, when Dan Straily will be recalled to start against the Cubs.
Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.