They’ve changed the rules in the MLS is Back tournament by allowing each team five substitutions rather than three in every game played in Florida’s stifling summer heat.

Minnesota United needed just two of them Sunday night in its tournament opener to turn a one-goal deficit for nearly 50 minutes into a 2-1 victory over Sporting Kansas City.

The Loons did so with goals in the 92nd and 97th minutes, deep into second-half stoppage time. Second-half subs Aaron Schoenfeld and Raheem Edwards sparked the comeback by providing bursts the Loons lacked for the first 60 minutes in their first game since March 7.

“That’s why you have a squad of players,” Loons coach Adrian Heath said after the game in a video conference call from Orlando. “As I said to the players before, everybody is going to be needed on this trip and in this tournament, so it was good they came off and had a solid contribution.”

Schoenfeld replaced injured striker Mason Toye in the 59th minute. At 6-4, he provided height in the penalty box that awakened his teammates. His range drew a foul and red card on Sporting K.C. goalkeeper Tim Melia in the 74th minute that changed the game.

Edwards replaced Robin Lod soon thereafter. Late in stoppage time Edwards kept the ball alive with work that created Kevin Molino’s winning left-footed goal.

The Loons, 3-0 for the season, lead the standings for the Supporters’ Shield, awarded for best regular-season record.

Toye’s injury came after he became a last-minute starter for Luis Amarilla, who tweaked his groin during pregame warmups. The team was already down injured starters Ike Opara and Ozzie Alonso.

“We were missing players before we came down here,” Loons midfielder Ethan Finlay said. “We had to show a lot of character in adversity and that’s what this group did. We pride ourselves on being a team that can grind games out. When there was an opportunity for guys to step in and show they can perform at this level, we saw that tonight. Two subs come in and make a massive difference.”

Schoenfeld’s shot from traffic in the 68th minute hit the crossbar but provided a second-half pulse his team so needed. In the 74th minute, Schoenfeld received Romain Metanire’s perfect lead pass, causing Melia to obstruct him just outside the penalty box. Melia received a red card for impeding Schoenfeld from reaching an empty goal, leaving Sporting Kansas City a player short for the game’s final 20 minutes.

“He was just bummed because he wants to get his first goal for the club,” said Finlay, who played with Schoenfeld in Columbus. “But I told him at that moment, he just changed the game for us.”

The Loons trailed 1-0 in the 92nd minute when Jan Gregus’ bending free kick went just over Schoenfeld’s head. But the ball bounded off Sporting winger Khiry Shelton’s chest and deflected for an own goal past backup keeper Richard Sanchez, who had entered when Melia was ejected.

In the days before the opener, Heath praised his team’s depth after it added Schoenfeld, Edwards, Jose Aja, Jacori Hayes, Marlon Hairston, James Musa and others last winter.

“I was really bullish about what this group could give us,” Heath said Friday. “One thing I do know, there’s maybe six or seven guys not starting who I know can go on the field and there won’t be any dropoff whatsoever. Everyone is determined, everyone is very motivated. Their opportunity is going to come, for sure.”

It came Sunday for Schoenfeld and Edwards.