Skowronek (shoulder) was signed to the Steelers' 53-man roster Tuesday, then placed on injured reserve Wednesday.
Skowronek was elevated from the practice squad for each of Pittsburgh's first two games but hasn't had much of a role in the offense. His move to injured reserve will keep him sidelined for at least the next four weeks but, presumably, he'll be a part of the 53-man roster once he's healthy after his signing to the active roster Wednesday.