The 71-times capped back-rower, who was national captain when he ruptured an Achilles playing for former club Scarlets ten months ago, is named in a starting XV that features ten internationalists.
Four of those started in last weekend’s epic 38-38 Calcutta Cup draw at Twickenham as Darcy Graham, Hamish Watson, Ben Toolis and WP Nel all return for tomorrow night’s vital match as Edinburgh look to keep their play-off hopes alive.
Scotland centre Matt Scott also makes a welcome return to action for the first time in over five months following a head injury sustained against Toulon back in October.
Edinburgh coach Richard Cockerill said: “We need to be as strong as we can be because we’ve had some poor results where we’ve slipped up where we shouldn’t have.
“That’s put us in a situation where, with four league games to go, we’re probably going to have to win all of them if we want to qualify for the play-offs.
“There’s been a lot of disruption over the last two months because of the Six Nations, but it is now back to the bread and butter of the league and making sure we get it right tomorrow night.”
The coach added: “It’ll be good to have John [Barclay] back on the field and he can share his experience with the rest of the team.
“He’s a fantastic player and his leadership around the group and his knowledge of the game is very, very good, and that could well be important for us in the run-in.”
Edinburgh team to face Leinster at BT Murrayfield in the Guinness PRO14 on Friday 22 March (kick-off 7.35pm) – live on Premier Sports
15. Dougie Fife
14. Darcy Graham
13. James Johnstone
12. Matt Scott
11. Duhan van der Merwe
10. Jaco van der Walt
9. Henry Pyrgos (captain)
1. Pierre Schoeman
2. Ross Ford
3. WP Nel
4. Fraser McKenzie
5. Ben Toolis
6. John Barclay
7. Hamish Watson
8. Viliame Mata
16. Cameron Fenton; 17. Allan Dell; 18. Simon Berghan; 19. Callum Hunter-Hill; 20. Magnus Bradbury; 21. Charlie Shiel; 22. Simon Hickey; 23. Chris Dean.
Unavailable due to injury: Lewis Carmichael, David Cherry, Luke Hamilton, Blair Kinghorn.