Scotland international George Turner will miss the remainder of the season for Glasgow Warriors after failing to make sufficient recovery from successive concussions.
The 26-year-old becomes the second Scotland player to be sidelined for a lengthy period with a concussion after Leicester Tigers bound David Denton.
Turner, who last played for Scotland during summer series last year suffered multiple head injuries this season after joining the Scotstoun Ground based outfit ahead of the 2018/19 season from Edinburgh.
Glasgow Warriors will also miss the services of Nick Grigg for the rest of the season following a surgery on his ankle that is expected to keep him on the sidelines for up to eight weeks.
Dave Rennie's side will line-up against Saracens on Saturday in the quarter-final of the Heineken Champions Cup at Allianz Park and also hold the top place in the Conference A table of Pro14 with 13 wins from 18 games.