Sean Lamont, Duncan Weir, Ryan Grant, Fraser Brown, Tim Swinson, Gordon Reid and Henry Pyrgos return to the matchday squad after Scotland duty while Lee Jones marks his new two-year deal with a start on the wing.
Leone Nakarawa (Fiji) and DTH van der Merwe (Canada) also return from international action.
Jon Welsh makes his first start of the season.
Gregor said: "We were disappointed with the performance and result down at the Scarlets last weekend and we are determined to deliver a much better performance on Sunday.
"The Dragons beat us home and away in the league last season and we will face a tough contest this weekend.
"It's great to be back home as we enter a really crucial part of the season. Sunday's game will be the start of a run of five GUINNESS PRO12 games to be played either at Scotstoun or across in Edinburgh at BT Murrayfield.
"The players get a huge boost playing in front of our own supporters and we're looking forward to the game this weekend.”
14 Lee Jones
13 Sean Lamont
12 Peter Horne
11 DTH van der Merwe
10 Duncan Weir
9 Nikola Matawalu
1 Ryan Grant
2 Fraser Brown
3 Jon Welsh
4 Tim Swinson
5 Alastair Kellock (Captain)
6 Leone Nakarawa
7 Chris Fusaro
8 Ryan Wilson
Substitutes
16 Pat MacArthur
17 Gordon Reid
18 Zander Fagerson
19 Josh Strauss
20 Tyrone Holmes
21 Henry Pyrgos
22 Connor Braid
23 Richie Vernon
Not available due to injury: Alex Allan (head), Adam Ashe (neck), Mark Bennett (leg), Dougie Hall (arm), Murray McConnell (leg), Sean Maitland (hamstring), Euan Murray (groin), Tom Ryder (neck) and Jerry Yanuyanutawa (knee).