– Three matches into Minnesota United FC’s inaugural Major League Soccer season, coach Adrian Heath has assembled three different variations of a back line.

The first two allowed 11 goals in two matches. The third gave up only two in a 2-2 draw against the host Colorado Rapids on Saturday.

“Well, we were better,” Heath said of his team’s defensive performance.

While allowing five and six goals against Portland and Atlanta, then only two on Saturday indicates improvement, the Rapids’ two goals were above average for a team that scored 39 goals in 34 matches last regular season.

The two Rapids goals were also on defensive errors. An intercepted back pass from midfielder Rasmus Schuller to center back Francisco Calvo led to the first goal 17 minutes into the match. And a quick Colorado counterattack beat the frazzled Loons for the equalizer in the 59th minute, moments after United had taken its first-ever lead on a Christian Ramirez goal.

“When we score, that next five minutes are very crucial,” Ramirez said. “That’s a learning point from us that we have to continue to learn from.”

Calvo, 24, has been the only member of the back line to play all three matches, making him the steadiest presence there for United. Against Colorado, he took on even more responsibility as team captain, with fellow center back Vadim Demidov on the bench and Brent Kallman in the lineup.

“I thought he did really well,” Heath said of Calvo. “Obviously, a mistake on the second goal, he didn’t clear it well enough. But the last 20 minutes when we needed him, he came up with some really big headers, came up with some really big last-ditch tackles.”

United played from the 70th minute on with just 10 players after the referee sent off left back Justin Davis, who had just come back into the lineup after sitting out against Atlanta. United already had used all of its substitutions on attacking players.

“I think if we had 11 players on the pitch,” Calvo said, “probably we win.”

Kallman said all the players who either entered the starting lineup for the first time or came on as substitutes did great work. Heath also called Kallman’s MLS debut “fantastic.”

“We did a little bit better job this week as a group of keeping the game in front of us, which was something we worked on,” Kallman said. “Instead of taking, maybe, too many chances, we just dropped … which I think helped limit [Colorado’s] opportunities a little bit.”

The match at New England on Saturday, though, will provide yet another shakeup to the back line. With Calvo on national team duty — along with Schuller and midfielders Kevin Molino and Johan Venegas — and Davis suspended, only Kallman and right back Jerome Thiesson likely will maintain their spots.

“I think at times tonight we showed that we can play,” Heath said Saturday. “We haven’t had a lot go our way. … But it’s the first point in the MLS, and we can build on that. … And, hopefully, one or two individuals will take a little bit of confidence into the next game.”