Glasgow Warriors head coach Gregor Townsend insists his side’s RaboDirect PRO12 clash with the Ospreys is the biggest game of their season.

Ospreys are currently fourth and the Warriors are fifth in the PRO12, with just four points separating the sides.

Glasgow have two home games in hand against Treviso and Edinburgh as they look to try and secure a play-off place and Townsend’s side, who beat the Scarlets last time out, is desperate for some momentum.

“This is our biggest game of the season so far with valuable league points up for grabs,” he said.

“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.

“We are well aware of the huge challenge we face tomorrow night and we're looking forward to playing in front of a big crowd at Scotstoun and the Glasgow support will have a key role to play.”

Townsend has made three changes to his side as Peter Murchie continues at full-back and Tommy Seymour and Niko Matawalu keep their places on either wing.

Finn Russell, 21, comes in at inside centre with Alex Dunbar moving outside in place of Richie Vernon, who has been named among the replacements.

Duncan Weir and captain Chris Cusiter continue their half-back partnership.

Pat MacArthur comes in for Dougie Hall at hooker and he'll play alongside props Jon Welsh and Gordon Reid in the front row.

Leone Nakarawa replaces the injured Tim Swinson in the second-row and partners Jonny Gray.

There are no changes to the back row with Rob Harley, Chris Fusaro and Josh Strauss all keeping their places in the starting XV.

The Warriors welcome back Scotland international Ryan Wilson, who has been named on the bench, while Sean Maitland continues his comeback from injury as a replacement.

Ospreys currently sit fourth but with the Warriors so close behind Steve Tandy is not underestimating the importance of the Scotstoun clash.

"This is a massive game for us and the group are under no illusions of the size of the task ahead over next couple of months,” he said.

“We are in fourth place at the moment but Glasgow are breathing down our necks with a couple of games in hand, which makes it more important than ever that we go there on Friday night and are on top of our game in all areas.

“Every player will need to know their role, pay attention to detail and be clinical in everything they do. There is absolutely no margin for error if we want to keep hold of a play-off spot so we know what we've got to do.

“It's all building up to be a real exciting end of season and we want to be involved right until the end.

“We realise that there is a lot of expectation on our shoulders being the only team from Wales in the mix again but that comes with being an Osprey and the boys have to stand up when the pressure is on.”

At Scotstoun Stadium, 7.35pm. Live on BBC Alba and BBC Wales

Referee: John Lacey (IRFU, 34th competition game)
Assistant Referees: Peter Allan, David Changleng (both SRU)
Citing Commissioner: Paul Minto (SRU)
TMO: Andrew McMenemy