Brebbia is scheduled to serve as the Giants' opening pitcher in a bullpen game Wednesday against the Diamondbacks, Maria I. Guardado of MLB.com reports.
Brebbia hasn't covered more than two innings or thrown more than 29 pitches in any of his 40 appearances this season, so he's unlikely to make it even once through the order before being pulled from the contest. The Giants haven't indicated that they'll deploy a primary pitcher behind Brebbia, but Sam Long is the most obvious candidate to cover multiple innings out of the bullpen if needed.