Susac (undisclosed) was placed on the 7-day injured list by Triple-A Indianapolis on Tuesday, Jason Mackey of the Pittsburgh Post-Gazette reports.
The Pirates reassigned Susac to their minor-league camp Wednesday.
The Pirates outrighted Susac off their 40-man roster Wednesday.
The Pirates selected Susac's contract from their taxi squad ahead of Sunday's game against the Indians, Alex Stumpf of DKPittsburghSports.com reports.
Susac, who went 4-for-13 with four walks in Grapefruit League action this spring, remains one of three catchers in the running to back up starter Jacob Stallings, the Pittsburgh Tribune-Review reports.
Susac agreed to a minor-league contract with the Pirates that includes an invitation to spring training, Adam Berry of MLB.com reports.
Susac was traded from the Orioles to the Royals for cash.
Susac was outrighted to Triple-A Norfolk on Thursday, Jon Meoli of The Baltimore Sun reports.
Susac was designated for assignment by the Orioles on Friday.
Susac (wrist) was reinstated from the restricted list Tuesday.