Wilkinson was added to the active roster as the 27th man for Saturday's doubleheader against the Diamondbacks and will start Game 1.
Wilkinson gave up four runs over 5.2 innings while working primarily as an opener during his last stint with the Giants. He'll now rejoin the big club to pitch in Saturday's twin bill and has a chance to remain in the majors beyond the weekend as one of the replacements for Carson Whisenhunt (elbow) and Adrian Houser (forearm).