Key players return for Scotland
Three players are returning from injury: flank John Hardie [return-to-play protocol], wing Sean Maitland [hand] and flyhalf Finn Russell [ankle].
Outside centre Mark Bennett also returns to partner Matt Scott in midfield, while fullback Stuart Hogg, wing Tommy Seymour and captain Greig Laidlaw start once again.
The three remaining changes to the starting pack are all promoted from the bench: Alasdair Dickinson and Ross Ford join Willem Nel in the front row, while Ryan Wilson starts in the back row alongside Hardie and No.8 David Denton.
Richie Gray will win his 50th cap for his country this Saturday having being reinstated in the second row alongside brother Jonny, while Sean Lamont could become the third Scotland internationalist to make 100 appearances – joining centurions Chris Paterson [109; 1999 to 2011] and Donna Kennedy [115; 1993 to 2010] – should he take to the field from the bench against the team he faced on his 2004 debut.
If Scotland are successful this Saturday they will face the winner of Pool A [Australia or Wales] at Twickenham Stadium the following weekend.
A win would guarantee the Scots a place in the quarterfinals of the World Cup for the seventh time since the competition's inauguration in 1987.
Cotter said: "Every Test match is a 'must-win' when you represent your country.
"We've put in a huge amount of work to get us to this point, and our performances and commitment have put us in a position to qualify for the last eight.
"We'll need to be up to the challenge, enjoy the opportunity, and maintain the awareness needed to play to our strengths and impose our game."
Scotland: 15 Stuart Hogg, 14 Sean Maitland, 13 Mark Bennett, 12 Matt Scott, 11 Tommy Seymour, 10 Finn Russell, 9 Greig Laidlaw (captain), 8 David Denton, 7 John Hardie, 6 Ryan Wilson, 5 Jonny Gray, 4 Richie Gray, 3 Willem Nel, 2 Ross Ford, 1 Alasdair Dickinson.
Replacements: 16 Fraser Brown, 17 Gordon Reid, 18 Jon Welsh, 19 Tim Swinson, 20 Josh Strauss, 21 Henry Pyrgos, 22 Peter Horne, 23 Sean Lamont.
Date: Saturday, October 10
Venue: St James' Park, Newcastle
Kick-off: 14.30 (13.30 GMT; 03.30 Sunday, October 11, Samoan time)
Referee: Jaco Peyper (South Africa)
Assistant referees: JP Doyle (England), Marius Mitrea (Italy)
TMO: Ben Skeen (New Zealand)
