There are options but no more Seranthonys. Rios is streaky but if the velocity is maintained, he'll be back. And Thompson of course is still learning to be more of a power arm out of the bullpen.
If there is a new face I think we might see one of the lefties either replace or supplement Morgan. This would not be Curtis. Tom Windle is inconsistent but has been much better this season. And Austin Davis could be another power arm (mid 90s) from the left side. With an open spot on the 40 one of these guys might join the bullpen rotation at some point.