Glasgow head coach Gregor Townsend has urged his team to stay tight against Ospreys in their biggest match of the season.
Fifth-placed Warriors go into Friday's Scotstoun clash four points behind their Welsh visitors in the RaboDirect Pro12, although the Scots have two games in hand on teams currently in the play-off positions.
Townsend said: "This is our biggest game of the season so far with valuable league points up for grabs.
"It was an important win for us last weekend because Scarlets were one place below us in the league and tomorrow we play the team that are one place above us, so this is a crucial game.
"Ospreys are a very physical side with a number of good playmakers in their backs so we'll have to be at our best defensively. Like any game against a top side, we'll have to seize any opportunity that comes our way."
Townsend has made three changes to his side with 21-year-old centre Finn Russell handed his fourth start as Richie Vernon drops to the bench.
Pat MacArthur comes in for Dougie Hall at hooker and Leone Nakarawa replaces the injured Tim Swinson in the second row.
The bench is bolstered by Scotland pair Ryan Wilson and Sean Maitland, the former back after RBS 6 Nations exertions, and the latter continuing his comeback from injury.