Dallas visits Allianz Field in St. Paul for a Sunday night soccer tilt against a Minnesota United team reliant on a Big D of its own.

The Loons, mired in a three-game slump against Major League Soccer competition, are staying competitive in large part because of their defense. Eight goals allowed through eight games ties the Loons for fifth-lowest total in MLS.

Coach Adrian Heath preaches a 10-player defensive effort to be successful. But the onus is on the back four, especially for a Minnesota team struggling to bury its chances. The Loons' eight goals scored ranks 21st out of 29 MLS teams.

Stalwart defenders include Micky Tapias and Michael Boxall, who rank first and second, respectively, in team minutes played against MLS opponents. Kemar Lawrence and DJ Taylor have each started six games.

"I think DJ's done particularly well of late," Heath said. "I think Kemar is one of the better defenders in the league. Micky and Boxy have had a really good understanding, so as a group that four has done really, really well. But they'd be the first to say it's been a lot of hard work in front of them."

Boxall and his mates appreciate the support. But the veteran defender knows the back line shares a heightened responsibility.

"At the end of the day, when you're looking at a goal conceded, you're looking at the back four and Dayne [goalkeeper St. Clair] as well," said Boxall. Now in his sixth season with the Loons, Boxall has made more than 150 game appearances across all competitions, the most of any player since Minnesota joined MLS.

"In the moments when it falls in our final third, it's really us five, six guys who are trying to protect Dayne's goal," Boxall said. "And we've for the most part done a good job, and it's just keeping that right frame of mind that we stay focused."

Recent losses have proven any lapse can trigger disaster. Chicago managed just two shots on goal and buried both in a 2-1 victory. Same story at home the following week against Orlando City. Traveling to Seattle last week offered more of the same. The Sounders got just three shots on goal, but one got through as Minnesota fell to 0-8 in the Emerald City.

"We've kind of lost on those small moments," Boxall said. "We played pretty well in those games. But when you're not picking up points, it doesn't feel too good."

Boxall and fellow defender Zarek Valentin supply experience and poise on the back line, which is a mix of cagey veterans and athletic youngsters.

"Micky's game sense helps him to know when to step and when to press," Boxall said. "When Zarek is beside me, he's similar in terms of his positioning and understanding of the game. I always know I can trust them."

"When DJ comes in, he's lively," Boxall said. "He's one of the better 1v1 guys. When he's having some of the best wingers dribble against him, you know he's gonna lock that down more times than not."

Valentin started the Seattle game and echoed Boxall's view about a defensive unit only being as good as its most recent result. Valentin started the season-opening 1-0 victory at Dallas in which Minnesota allowed just one shot on goal. As the Loons pursue their first home victory of the season Sunday in the rematch, players know positive results aren't transferable.

"We had success against them early in the season," Valentin said. "But that, as everyone knows, doesn't guarantee anything at all."