Greiss (lower body) underwent a procedure Monday and is currently weighing his options, Lou Korac of NHL.com reports.
It wouldn't be a surprise if Greiss sat out the remainder of the regular season. The 37-year-old netminder has a 7-10-0 record this season with a 3.64 GAA and an .895 save percentage in 21 appearances. St. Louis brought up Vadim Zherenko from AHL Springfield on Monday to back up Jordan Binnington.