The Pirates optioned Jose Osuna and Kyle Crick to Class AAA Indianapolis on Monday, further clarifying their opening-day roster.
Lefty Kevin Siegrist, a non-roster invitee, was also reassigned to minor league camp.
The moves mean the Pirates will go with a four-man bench, at least through the first series of the season in Detroit. The final three bullpen spots will go to some combination of Rule 5 pick Jordan Milbrath, lefty Josh Smoker, Dovydas Neverauskas and Edgar Santana.
Crick, the right-hander who joined the team in the Andrew McCutchen trade, pitched in more spring training games than any other Pirate.