Sean Maitland misses out on the Millennium Stadium match due to injury but Gray, Ryan Grant and Stuart Hogg are all set to start at lock, prop and full back respectively.
Gray, who came on as a replacement in the third Test win over the Wallabies, says that working with the likes of Gatland, Howley and skipper Sam Warburton will help in the preparations for this weekend, although he admits that the prospects of a first Scottish win in Wales since 2002 rest largely on how his side perform themselves on Saturday.
"Being on the Lions tour to Australia with a squad coached by Warren - and with Welsh No2 Rob Howley as attack specialist - gives you an insight into how they will play," said Gray, who is ready for a fast-paced encounter in the final round of the RBS 6 Nations.
"The Lions guys in Scotland's set-up will be feeding that back. But come the weekend it will be all about concentrating on us and getting our part right.
"Listening to Wales over the last few days, they're pretty hurt and they'll want to do something in front of their own fans to make amends. England played very well and managed to stop them behind the gain line. That meant Wales couldn't really get much momentum.
"They will be extra keen to end their campaign on a positive note. I'm expecting a fast and physical game as you always get with the Welsh. The stadium roof will be closed as well so that will make the pace even quicker."
Neither Wales or Scotland are in the hunt for the Championship crown this weekend but Gray's fellow second row Jim Hamilton sees no reason why his side can't change that stat in the coming seasons.
And while Wales have won the last two tournaments and Scotland haven't triumphed since the last year of the Five Nations in 1999, Hamilton is convinced that a title isn't just a distant dream for this current crop of Scottish players.
"I genuinely believe that we are getting closer to that point where we can challenge," said Hamilton, who left Gloucester for Montpellier last summer.
"I know it's all if, buts and maybes and that people have heard it all before…but I wouldn't keep coming back, leaving my two kids and wife at home in France, if I didn't believe in this squad that we have.
"You can see in certain aspects of the France game that we are definitely going in the right direction. We were comfortable against France at times and we have only got ourselves to blame. Maybe a lot of supporters are getting sick of hearing that but as players we want that consistency and we want to win games.
"Me personally, I am getting on a bit now and my ambition before I finish playing is to win a Championship. If we keep putting in performances like we did against France and keep believing in what we are doing, there are a lot of young players in this squad who can take us there."