Finn Russell, Stuart Hogg, John Hardie, Sean Maitland and Ross Ford have all recovered from injury to start for Scotland against Samoa on Saturday.
Scotland will reach the quarter-finals of the World Cup should they beat the Pacific Islanders but they would have to rely on Japan losing to the USA should they lose.
The quintet are part of seven changes made by head coach Vern Cotter as centre Mark Bennett and prop Alasdair Dickinson also return to a side
Should versatile back Sean Lamont come off the bench, he will become the third Scotland international to earn 100 caps.
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: Stuart Hogg (Glasgow Warriors); Sean Maitland (London Irish), Mark Bennett (Glasgow Warriors), Matt Scott (Edinburgh), Tommy Seymour (Glasgow Warriors); Finn Russell (Glasgow Warriors), Greig Laidlaw (Gloucester, Capt.); Alasdair Dickinson (Edinburgh), Ross Ford (Edinburgh), WP Nel (Edinburgh); R Gray (Castres), J Gray (Glasgow Warriors); Ryan Wilson (Glasgow Warriors), John Hardie (unattached), David Denton (Edinburgh).
Replacements: Fraser Brown (Glasgow Warriors), Gordon Reid (Glasgow Warriors), Jon Welsh (Newcastle Falcons), Tim Swinson (Glasgow Warriors), Josh Strauss (Glasgow Warriors), Henry Pyrgos (Glasgow Warriors), Peter Horne (Glasgow Warriors), Sean Lamont (Glasgow Warriors).