Dominguez was placed on the 15-day injured list Sunday due to right triceps tendinitis, Matt Gelb of The Athletic reports.
Dominguez was unavailable Saturday after experiencing discomfort playing catch earlier in the day. He'll now formally be placed on the IL, but the Phillies are hopeful he'll be ready to return in the minimum amount of time if his upcoming MRI comes back clean, according to Todd Zolecki of MLB.com. In the meantime, David Robertson profiles as the best bet for saves out of the bullpen, though it's possible interim manager Rob Thomson opts for a closing committee. Prior to going down with the injury, Dominguez had maintained a 1.64 ERA, 0.91 WHIP and 54:14 K:BB to go with nine saves across 44 frames on the season.