The centre's absence means a reshuffle in the back line, but Greig Laidlaw is retained at scrum-half despite suggestions at the team announcement he would revert to fly-half if De Luca missed the RaboDirect PRO12 clash.
Laidlaw will be partnered by Piers Francis at fly-half, with James King at inside centre and Matt Scott at outside centre, while the back three is comprised of Tim Visser, Lee Jones and Greig Tonks.
Bradley said: "It's disappointing to lose a key player like Nick for such a big game, but James has performed very well when given the opportunity this season and is desperate to get out there tomorrow.
"These are huge games for the players and the fans and I'm happy with the balance of the team and the firepower available from the bench going to Scotstoun tomorrow for what will be a hugely physical and intense match with our biggest rivals."
- Sports & Recreation
- Greig Laidlaw
- Greig Tonks
- De Luca