Tests on Blackburn's injured wrist came back clean but there is no timetable for his return, Jane Lee of MLB.com reports.
He will miss at least several starts, according to Susan Slusser of the San Francisco Chronicle, so it's possible he does not return at all this season. Blackburn has a 3.22 ERA and 1.26 WHIP in 10 big-league starts, but his 22:16 K:BB in 58.2 innings suggests he has extreme negative regression coming whenever he returns to the mound.