Montgomery (knee) threw a bullpen session Tuesday, Nick Piecoro of The Arizona Republic reports.
Montgomery exited the throwing session "feeling good" according to manager Torey Lovullo, as the left-hander works his way back from right knee inflammation. Montgomery has an outside chance of returning from the 15-day injured list Sunday at home versus the Blue Jays, though it seems more likely the team will wait until after the All-Star break to activate him.