Dominguez was unavailable for Saturday's games against the Mets due to tightness in his right triceps, Todd Zolecki of MLB.com reports.
Dominguez felt some tightness while throwing Saturday morning. He noted some concern because it's an injury related to his arm, but more specific news is expected Sunday. David Robertson collected a two-inning save in the second game of Saturday's doubleheader in Dominguez's absence.