Vern Cotter has challenged his Scotland side to raise their game against Samoa on Saturday and secure a victory which would put them through to the quarter-finals of the Rugby World Cup.

Ruthless South Africa knocked Scotland off the top of Pool B by consigning them to a 34-16 defeat at St James' Park last weekend.

The Springboks are assured of top spot after reeling off three wins in a row following their sensational defeat to Japan.

Either Scotland or Japan will join South Africa in the last eight from the group.

Scotland are two points clear of surprise package Japan, who face the United States on Sunday, so a win for Cotter's men would ensure they will face either Australia or Wales in the quarter-finals.

And the Kiwi coach is calling on his players to rise to the occasion when they return to the field in Newcastle this weekend to face a Samoa side who have only managed victory against the USA.

He said: "We are playing this game as a qualifying game. We are enjoying being in the situation to qualify.

"We know it's going to be a very tough game. The guys are preparing for a difficult match. This probably rounds the whole thing up. We've got 80 minutes and we need to put in a very, very good performance."

Cotter added: "We know that we'll have to improve and we're looking for a much better performance in the contact area. We learned a lot from the South Africa game.

"We need to perform in certain areas better than we have done.

"We know they have threats all over the park. We are expecting a very, very tough contest."

Finn Russell, John Hardie and Sean Maitland return from injury, while Jonny Gray, Ross Ford and Matt Scott have been passed fit and Mark Bennett, Alasdair Dickinson and Ryan Wilson are recalled.

Sean Lamont will be hoping to get the nod to come off the bench and become only the second Scottish man to win 100 caps.

Samoa wing Alesana Tuilagi will not feature after he was given a five-week ban for striking Japan's Harumichi Tatekawa, while Manu Leiataua will make his World Cup debut.

Scrum-half Kahn Fotuali'i will captain Samoa after back-rower Ofisa Treviranus was left out of the squad as head coach Stephen Betham makes seven changes to the side beaten by Japan. 

Betham said: "It's very important. At the moment we have a country that is feeling a bit sad. Not just that, we’ve got a lot of talent but we haven't shown it. We haven't shown anything of it all the tournament.

"We can be dangerous on any day, but we have to show up; not just on the field but off it. That motivation is there for us and we’ve got to play for ourselves."