Russell was a league and cup winner with Ayr three years ago before becoming a professional player and everyone at Millbrae is delighted to see him back in a pink and black shirt. He'll line up alongside younger brother Archie, who joined Ayr last season, to make his long-awaited return from injury.
"It's great for the BT Premiership to have the link with the pro clubs," says Ayr head coach Calum Forrester, "and with international players getting released on a weekly basis, it will only raise the profile of our club game."
He continues: "Mansfield is always a challenging environment to play in and we will need to improve on last week's performance if we are to get the result we desire."
The vastly experienced second row Scott Sutherland makes his first appearance of the season, with Danny McCluskey moving to the wing, and hooker David Young, centre Ross Curle and scrum-half David Armstrong return to the starting line-up.
On the bench, young guns Robbie Smith, Adam Prentice and Craig Stevenson take their place with Cameron Taylor and Frazier Climo.
15. Grant Anderson (c); 14. Danny McCluskey, 13. Archie Russell, 12. Ross Curle, 11. Craig Gossman; 10. Finn Russell, 9. David Armstrong; 1. George Hunter, 2. David Young, 3. Steven Longwell; 4. Robert McAlpine, 5. Scott Sutherland; 6. Will Bordill, 7. Gregor Henry, 8. Blair Macpherson.
16. Robbie Smith, 17. Adam Prentice, 18. Craig Stevenson, 19. Cameron Taylor, 20. Frazier Climo.
Kick-off 3pm. Follow the scores live on Twitter or watch live via the Scottish Rugby YouTube channel.