Bristol Bears are this season’s leading try scorers (38) and points scorers (302) from their eight matches to date.
Lam makes six changes from the Premiership semi-final defeat, as Alapati Leiua and Harry Randall return to the backline.
In the pack, Dave Attwood lines up against his former side, while Dan Thomas, Yann Thomas and Kyle Sinckler are also included.
John Afoa is listed among the replacements and could feature in his fifth European final if called upon.
Bristol Bears team to face RC Toulon in the European Challenge Cup final at Stade Maurice-David (8pm KO BST):
15. Max Malins; 14. Luke Morahan, 13. Semi Radradra, 12. Siale Piutau, 11. Alapati Leiua; 10. Callum Sheedy, 9. Harry Randall; 1. Yann Thomas, 2. Harry Thacker, 3. Kyle Sinckler, 4. Dave Attwood, 5. Chris Vui, 6. Steven Luatua (c), 7. Dan Thomas, 8. Ben Earl.
System players: 16. George Kloska, 17. Jake Woolmore, 18. John Afoa, 19. Joe Joyce, 20. Jake Heenan, 21. Tom Kessell, 22. Piers O’Conor, 23. Niyi Adeolokun.
Unavailable: Will Capon (ankle), Max Lahiff (calf), Charles Piutau (achilles), Nathan Hughes (ribs), Andy Uren (foot), Henry Purdy (hamstring).