EAST LANSING, Mich. -- Things change so quickly around here, it's worth pausing to savor the moment. From behind a door across from the Michigan State locker room Saturday afternoon burst Kenneth Walker III. The whole world wants him at this point.

After rushing for 197 yards and five lightning-bolt touchdowns in a 37-33 win over No. 6 Michigan, the toast of college football is yours for a couple of minutes. What do you ask?

Could the Wake Forest transfer have imagined all this, perhaps becoming the Heisman Trophy favorite in a season that has lacked a clear top player in the nation?

"No sir, I did not," said Walker, a 5-foot-10, 210-pound package of sinew and speed who has redefined the Heisman race nine weeks in. "I believe in this team 100%, and they believe in me. That means so much more."

But how did it happen so fast? The staff at No. 8 Michigan State certainly couldn't have told this Tennessee native he could lead the country in rushing and dominate doing it.

"I knew Coach [Mel] Tucker was an old-school kind of coach," Walker said. "I know he liked to run the ball. We talked about being physical. I knew he wanted to run the ball. I had it in my mind how it was going to be."

The whole world appears to want Tucker, too. In 20 short months, he has dived into the transfer portal headfirst building what can only be described now as a national power.

The Spartans came into the game ranked eighth but left as perhaps the best story in the game entering Tuesday's first release of the College Football Playoff Rankings for the 2021 season.

"I don't believe in self-imposed limitations," said the 49-year-old Tucker after becoming the first Michigan State coach to win his first two games against Michigan.

The plucky Spartans moved themselves to 8-0 while moving the needle toward a playoff berth … but that's for down the road.

Away from prying eyes for just second, Tucker relaxed to explain how he landed Walker.

It was no secret his program needed help. The Spartans averaged 2.5 yards per rush last season, putting them near the bottom of the Big Ten. In that 2-5 year, Michigan State still beat Michigan, so there was hope.

Meanwhile, Walker had become frustrated with Wake Forest coach Dave Clawson's zone read spread. It's ravaging the game itself these days but wasn't a fit for Walker.

What Tucker wanted was uttered by a quiet man standing on the 15-yard line following the wild party that followed at Spartan Stadium.

"He reminds me of Jevon Ringer," former Michigan State coach Mark Dantonio remarked.

Ringer, the former consensus 2008 All-American, ran for almost 4,400 career yards at Michigan State before a four-year NFL career. He has the same quick-twitch ability as Walker. Ringer also showed up at practice this week. The comparisons to Walker were there in the flesh.

"We have an offense that translates to the NFL," Tucker said. "We're under center. We're in the gun. We're in pistol. We check plays. We use pass pro to improve his pass protection. But we needed a difference maker because we're committed to running the football. This is not Air Raid."

Tucker saw it in Travis Prentice. In 1999, Tucker was the defensive backs coach at Miami (Ohio) when Prentice ran for 1,600 yards and 17 touchdowns. The previous year, Prentice was the MAC player of the year.

"It was really tough to try to figure out how to get him practice reps," Tucker said.

Walker can't be kept off the field during the week at Michigan State. Even as the Spartans hit in full pads Tuesdays and Wednesdays, Walker might take 20 snaps per practice as a precious commodity to the team.

"It's really hard to rein Kenneth in because he does not loaf," Tucker said. "He goes hard. We have to pull him back. If we give him the ball in practice, he's going to go."

The wind-up toy nature of Walker was there for all to see Saturday. Michigan State was down 10-0 when the junior exploded for his first touchdown run. It might have been his best of the day. Hemmed in up the middle, Walker bounced outside and zipped 27 yards for what may or may not have been a touchdown. Replays showed Walker flipped the ball out of his hands just as he crossed the goal line. Review upheld the touchdown.

"Good luck tackling him," Michigan State quarterback Payton Thorne said. "When you hit, he's rock solid, too. He's built of granite."

The Michigan lead grew to 30-14, and play calling became a balancing act. How do you lean on a go-to tailback when you're down by 16?

Tucker and his staff chose not to. Walker didn't touch the ball on 15 of 16 Spartans snaps as the Wolverines built their lead.

But he still broke through twice in that span, scoring on a 1-yard run that cut the lead to 30-22 after a two-point conversion. Following Walkers' electric 58-yard touchdown dash and another two-point conversion, the game was tied at 30.

"This is a huge stage. The whole world is watching," Tucker said of Walker. "They got a chance to see what type of player he is. Any type of consideration he's getting for Heisman is well deserved.

"This is a game we had to have."

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Michigan certainly had its chances, but the Wolverines blew it again in the Paul Bunyan Trophy game. Michigan's game-winning drive was set up when freshman quarterback J.J. McCarthy fumbled at his own 45. Five plays later, Walker rushed 23 yards for the winning score, his fifth touchdown of the game. No player has ever done that to Michigan.

McCarthy, a five-star prospect, has mostly been a change-of-pace guy to Wolverines QB Cade McNamara this season. But no doubt coach Jim Harbaugh will have to answer questions next week on why a freshman was in there at such a key time, especially when McNamara would have been the star if Walker hadn't broken out. The junior threw for a career-high 383 yards.

Harbaugh is now 2-13 against top 10 teams at Michigan.

"To see Paul in [the locker room] is special," Tucker said of the trophy that goes to the winner. "I told him he's where he belongs."

That's a bit of lasting tradition that may calm fears here. Sparty will always endure, at least it has lately winning 11 of the last 15 meetings against its fierce rival.

Walker was the main reason this time.

We already know the coach who assembled the pieces to this 8-0 start could be a short-timer. After a prominent career as a defensive coordinator in the NFL and SEC, Tucker spent exactly one season at Colorado (5-7 in 2019) before bolting for Michigan State.

Barely halfway through Year 2, Tucker has built a power that was projected by Las Vegas before the season to win 4.5 games.

"There's no coach in the country I'd rather play for," Thorne said.

Tucker left Kirby Smart's side as Georgia defensive coordinator in 2018 to take the Colorado job. After 20 months in East Lansing, Tucker is being mentioned prominently in a coaching carousel that already threatens to spin out of control this season. Six coaches have lost their jobs going into Week 10.

USC and LSU, among others, are looking. It's no secret that LSU, where Tucker coached defensive backs for Nick Saban in 2000, could come calling.

That's why they should all take a good look. Things are changing so fast in the game and around here, take time to soak it in. That's what Tucker did a quarter century ago when he was a raw graduate assistant under Saban.

And so that's where we are in one whirlwind afternoon witnessed a breakout star (Walker) and a heartbroken Michigan. Not that they care at Michigan State.

The Big Ten East is within Sparty's grasp. So is the Big Ten and a CFP berth.

"I remember we used to walk over the stadium on game days," Tucker recalled. "It was normally an 8-minute walk [that took] like 3 minutes. Nick was cruising. He was flying. He couldn't wait to get over there."

Spartans everywhere can't wait to see if Tucker stays, even if their star running back must eventually go. After all, the whole football world wants him.