Minnesota United coach Adrian Heath is convinced his team will score more than enough goals this season, even when it hasn’t.

Then there was Saturday’s 2-0 loss at Chicago, where it surrendered two goals in the first 34 minutes after it had allowed just one in three previous games.

United only scored twice in those three games but had enough chances in all three that Heath called himself unconcerned.

On Saturday, United didn’t generate a truly dangerous one until second-half substitute Romario Ibarra’s shot from 10 yards away was stopped in the 92nd minute.

“It wasn’t an acceptable performance,” Heath said afterward. “We’re better than that.”

Heath on Saturday started an 11 that was the same through the back line — a lineup that included defender Eric Miller and Brent Kallman — as he had the previous three games. He made those changes after captain Francisco Calvo was suspended for a game and after United allowed seven goals combined in games against New York City FC and Toronto.

That addressed the team’s defensive issues, but on Saturday United couldn’t stop the Fire’s counterattacks on an evening when Chicago could have scored three or four goals by halftime.

Nor could United manage much of a scoring chance other than Romario Ibarra’s late opportunity and Ethan Finlay’s open first-half shot that was deflected wide.

Afterward, Heath lamented his team’s lack of “spirit,” “determination” and “fight” against an opponent that recorded its third consecutive shutout.

“I don’t think we had enough energy,” Heath said. “We didn’t get forward with any conviction. I don’t think we ever got going this evening. We were second-best most of the evening.”

Heath stuck with Finlay and Miguel Ibarra playing just beneath striker Angelo Rodriguez and star Darwin Quintero, who came off the bench for the second consecutive game. He did so both because Quintero is on the mend from an injured ankle and because he didn’t want to change a team that had gone undefeated in its past three games (1-0-2).

By halftime, he called upon Quintero and Abu Danladi for Finlay and Rasmus Schuller, seeking that missing energy.

“I thought he had a bit more energy this evening when he came on,” Heath said about Quintero. “He turned the ball over a couple of times, but showed great reaction to get it back, which is pleasing. We know his quality. We’ve got to wait for that opportunity and hope he gets a little break that gives him a little spark to progress and move on.”

Heath later sent Romario Ibarra into the game for more offense as well.

“To be fair to Rasmus and Ethan, it could have been any one of the 10 that we could have changed because I don’t think that was a good enough performance,” Heath said. “It was one of them evenings where, as a group, we didn’t do ourselves justice. We’ve won three games on the road against teams that are good at home. We just didn’t get going. I’m trying to think of anybody who did themselves justice tonight.”

The one exception: captain and veteran midfielder Ozzie Alonso, who played ill against a dominant Chicago midfield led by Dax McCarty with Bastian Schweinsteiger joining the attack behind him.

“He has been sick for a day,” Heath said. “For him to put that performance in and keep going shows a lot of character from him.”

Still, overall Heath called it a “disappointing evening.”

“We can’t just keep saying we’re better than that,” Heath said. “We have to show it.”