Arrighetti (foot) threw a bullpen session Tuesday and is scheduled to begin a rehab assignment at Triple-A Buffalo on Thursday, Mitch Bannon of The Athletic reports.
Arrighetti landed on the injured list July 25 due to nerve irritation in his right foot, but he's made encouraging progress in his recovery and even said he'd be willing to pitch in Toronto's current series against the Astros -- his former team -- if needed. He won't be eligible to return from the IL until Sunday, however, and the Jays will likely hold off on having him make his team debut until mid-August.