The 23-year-old had been seen as a creator after his starring role as a playmaker on the opening day of the season when he scored and dictated play against Wolves when Alan Stubbs was in charge.
But he is happiest doing the ugly jobs and his combative presence was a key factor in the Millers ending a running of seven successive Championship defeats with a 2-2 draw at Ipswich Town last Saturday in Jackett’s second match in charge.
“I would say it’s probably my best game in a Rotherham shirt,” Vaulks said.
“It’s something I didn’t get to show the fans at the club under Alan Stubbs. That’s nothing against him at all. He brought me to Rotherham and I’m very grateful to him.
“But the dogged side of the game is what I actually enjoy - heading, running and kicking and using my fitness, which I was allowed to do against Ipswich. Hopefully, I can do that more.”
Vaulks found himself in and out of the side as he failed to replicate his August 6 form and the Millers slipped to the foot of the Championship table, leading to Stubbs’ sacking.
Jackett turned to him for the Portman Road clash when skipper Lee Frecklington was ruled out with an ankle injury, and the former Falkirk player, who joined the Millers in the summer, is hoping he has done enough to keep his place under his new manager.
“My Rotherham career started well, then dipped a little bit with one thing and another,” he said. “I think I could have done better. As a team, obviously, if you get beat every week, it’s tough.
“I’ve been used, in my three years professionally, being up near the top of the table in Scotland. Here, it’s a different kettle of fish, I suppose.
“I’ve really enjoyed it. It’s a learning curve. You build confidence individually as the squad builds confidence, so hopefully I can keep working hard and trying to get as many games as I can.”
Town boss Mick McCarthy is certain Rotherham chairman Tony Stewart has made a shrewd move in hiring Jackett, an experienced managerial campaigner in the second tier and a promotion winner with all of his previous clubs, Swansea City, Millwall and Wolves.
“Kenny certainly gets his teams well organised,” he said. “I see him on the sidelines in his suit looking all smart, but he’s just like the rest of us in terms of what he demands out of his team - to be hard-working, to put your foot in. He’s had pretty good success with all his teams in the Football League.
“Wolves missed out on the Championship play-offs to us by only a single goal two years ago. He knows what this division is all about.”
Jackett took the New York Stadium hot-seat less than two weeks ago and has a big survival scrap on his hand. The Millers are eight points adrift of safety with seven points from 15 games.
It brought back memories for McCarthy of a similar mission he completed four seasons ago in East Anglia.
“It’s not going to be easy. Rotherham are fighting for their lives,” he added. “When I first arrived here (in November 2012), we had seven points after 13 games. We went to Birmingham, produced a real scrapping performance, nicked a goal, nicked a win and it set us off.
“You’re not going to get your way out of danger by playing silky football. It really will be a bit of a siege mentality, backs to the wall, be hard to beat. You’ll always get a chance at the other end.
“Nick a win and it can change the course of your season.”