The Rangers skipper reserved special praise for the influential pair who have thrived since Stuart McCall opted to field a back three, giving the wing-backs license to get forward and attack.
Wallace has been particularly impressive since the tactical change, scoring an important goal in the game against Hibernian before playing a big role in the build-up to Kenny Miller’s first of 2015.
McGregor has also adapted well to a tactical tweak, firing in the second goal against Cowdenbeath on Saturday, with McCulloch certain that his new position suits the 29-year-old’s playing style.
"They have both had license to go forward in the past couple of games - sometimes at the same time - which we've not had before,” he said.
"I think that it suits Darren, because he is an aggressive player and good in the air as well - it was some strike at the weekend from him.
"Waldo needs a license to go forward and that's what he's been getting recently, in the last two or three games he's probably turned in the best performances he has this season, so I'm delighted for him as well."
The Light Blues skipper also revealed that McCall has more changes in store which are being worked on in training as they aim to secure second-place - finding their form just as Hibernian seem to be losing theirs, suffering two straight defeats against the Gers and Raith Rovers.
Rangers sit level on points with second-placed Hibs with a game in hand, with a difficult contest against Hearts at Ibrox next up on Sunday. The Gers need to win the game to keep the pressure on Alan Stubbs’ side, or they risk falling behind again after only recently managing to close the gap with wins against Hibs and Cowdenbeath in the Scottish Championship.