Shea was scratched for Thursday's 2-1 overtime win over the Ducks, the 10th time in 12 games he's sat out.
Shea agreed to terms on a one-year, two-way contract with Pittsburgh on Monday.
Shea was put on waivers Thursday, per CapFriendly.
Shea played in 31 games as a rookie this season but managed just one point to go with 24 hits, 24 blocks and 17 shots.
Shea (not injury related) will be in Monday's lineup against the Maple Leafs.
Shea is stuck in Buffalo due to an immigration problem but is expected to arrive in Toronto in time for Monday's matchup, Matt Vensel of the Pittsburgh Post-Gazette reports.
Shea was recalled from AHL Wilkes-Barre/Scranton and will be in Monday's lineup against the Rangers.
Shea was demoted to AHL Wilkes-Barre/Scranton on Sunday, per CapFriendly.
Shea was called up from AHL Wilkes-Barre/Scranton on Friday, Seth Rorabaugh of Tribune-Review Sports reports.
Shea was reassigned to AHL Wilkes-Barre/Scranton on Friday.