Lin (jaw) threw a 45-pitch live bullpen session Friday, Alex Weiner of ArizonaSports.com reports.
Lin is scheduled to throw two more side sessions, with Diamondbacks farm director Shaun Larkin noting that the southpaw will be six weeks removed from undergoing jaw surgery at that point. The 20-year-old required surgery after he suffered multiple facial fractures when he was struck in the face by a foul ball while sitting in the dugout during a Double-A Amarillo game in late April. Larkin noted that the Diamondbacks are optimistic Lin will be ready to cover five innings and 75 pitches around June 14, so that's presumably his target date for a retrun from Amarillo's 7-day injured list.