Instructions be damned, the sophomore forward limped around MSU’s huddle early in the second half — with no disrespect to his head coach but all attention paid to his ailing knees — grimacing in pain, walking on one good leg.

Playing through pain he described as “ridiculous”, Roe was inspirational in the No. 5-seed Spartans’ come-from-behind 59-52 win Friday at the Edward Jones Dome in St. Louis. He finished with just six points and five rebounds but his value was incalculable.

His 27 minutes were the most since early December and his tenacity and grit were the microcosm of the team the Spartans have become. With his help, MSU (27-8) is heading to its record seventh Elite 8 in the last 12 years.

“Every rebound was painful,” Roe said of his right knee. “Every move I made, not so much the lateral stuff, but the quick jumps and quick moves were painful. I had to say, ‘Forget the pain, remember why I’m playing.’ I’m playing not because I like pain, but because I want to win a championship.”

At the most crucial juncture of its season, MSU competed without one of its best players (junior guard Kalin Lucas) and partially one of its best defenders (junior guard Chris Allen) because of injury. But sophomore forward Draymond Green said peaking chemistry allows MSU to make up for lost personnel.

“Our chemistry is building,” Green said. “It has to build at this moment. You can’t win anything as an individual. And with our chemistry building, that’s why we’re where we are now.”

Without Lucas, back-up sophomore guard Korie Lucious had 10 points, six rebounds, four assists and four steals (and just two turnovers) in 39 minutes. Junior guard Durrell Summers, who now has scored in double figures in his last six NCAA Tournament games, led all scorers with 19 points.

During deadball situations, Roe paced around the key and, while on the bench, stood behind his teammates waiting to re-enter. The ailing knee recently has kept Roe out of second halves, but not Friday.

“I just can’t believe what the guy is giving us,” MSU head coach Tom Izzo said. “Every player knows it. The doctors know it. They guy has more courage than just about anybody I’ve ever coached.

“At halftime, he just lays there and gets worked on. I don’t know what he’ll be able to do on Sunday, but I’m not betting against him anymore.”

Roe was key in MSU’s spurt out of halftime — at which it trailed, 29-22 — as the Spartans went on a 14-5 run to take their third lead of the game.

Roe ran the length of the floor — which he said he needed to do in order to gain the momentum for the play — before grabbing a rebound off a Lucious miss and slamming it home.

Minutes later, Roe followed with a lay-up and a nifty assist to a wide-open Allen while Roe was falling out of bounds. The Allen bucket tied the game at 34 and MSU had a stranglehold on the pace from that point forward.

As the darlings of the tournament, a huge contingent from Cedar Falls, Iowa, made the trek to see the No. 9-seed Panthers (30-5) in their first Sweet 16 and filled in vacated seats of Ohio State and Tennessee fans who left after the first game — in addition to Northern Iowa’s allotted seats.

“We just didn’t want it to end — that’s the biggest thing,” said Northern Iowa guard Ali Farokhmanesh, who hit the game-sealing bucket last weekend against No. 1 overall seed Kansas and graced the cover of Sports Illustrated this week. “I think we enjoyed playing with each other so much that, yeah, we just didn’t want this to end.”

While the Panthers look ahead to next season, the Spartans look ahead to No. 6-seed Tennessee on Sunday, which defeated No. 2-seed Ohio State, 76-73, Friday. Game time is set for 2:20 ET Sunday.

The winner will head to the Final Four in Indianapolis next weekend, which would be MSU’s second straight trip and a nation-best sixth trip to the Final Four in the last 12 years.

“There’s a lot at stake,” Izzo said. “The Final Four is — now you can finally talk about it — what you play for. And there’s no question Tennessee is a good team. … My whole staff will be working for the next 40 hours and we’ll see what we can do.”