Glasgow will also face Cardiff Blues and Exeter in Pool Two but it is the double header with Toulon which will whet the supporters appetites.
Gregor told glasgowwarriors.org: "Toulon are European Cup champions and almost did the double, they've got a world class team and they've built a global reputation on who they've signed and the passion of their supporters, so I can't wait, it will be a cracking game at Scotstoun.
"I've played at the Stade Mayol twice in my career and they were definately highlights. It was an experience and atmosphere like no other at club level.
"The pitch is great, it's very quick, the weather is usually beautiful and the crowd are fantastic. The whole occasion will be great for our players."