Minnesota United's playoff-clinching 2-0 victory over Vancouver was its first shutout since it beat D.C. United by the same score on July 16.

That's 14 games and 85 days between.

Or simply — according to Loons goalkeeper Dayne St. Clair — "a long time."

It was only the Loons' fifth clean sheet of the season, but it was reflective of the team's play during an 8-1-2 summer surge. After that came an 0-5-1 stretch in which the team was outscored 14-2 — and then Sunday's victory.

Now the Loons are headed to the MLS Cup playoffs — Monday's first-round game at FC Dallas — for the fourth consecutive season.

Loons coach Adrian Heath credited his defensive back line, particularly resurgent veteran center back Michael Boxall, for keeping its shape and composure all afternoon Sunday.

"The back four," Heath said succinctly when asked about the shutout.

Center back Brent Kallman attributed it to improved discipline from the team's attackers through its defensive spine. But he wasn't about to quibble with Heath's praise for Kallman, Boxall and fullbacks Kemar Lawrence and DJ Taylor on a back line that has missed injured anchor Bakaye Dibassy since August.

"I'm not going to fight him too much on that," Kallman said.

It was Boxall's own goal that sparked three goals surrendered to Dallas within four minutes in a 3-0 home loss the last time these teams met, on Sept. 3. Heath called it "five minutes of madness" afterward.

Heath said he'll speak to his players about that fleeting time but won't show it to them again. That was the second consecutive loss in that 0-5-1 stretch.

On Sunday, Heath called Taylor probably his team's best player on the field and Boxall his old self.

"I thought Boxy might have had his best game of the season, like the Boxy we've been used to," Heath said. "I think he'd be the first to say, by his really high standards, he has not been there as much this year.

"... That was more like us. When we're like that, we're tough to break down."

Added Kallman: "The discipline was better, with and without the ball. We felt like we were more in control. A lot of times when you're giving up goals, a lot of people point at the back line when it really takes everybody to defend."

Loons star playmaker Emanuel Reynoso proved as much when he created the only goal his team needed by forcing a turnover nearly 40 yards from the Vancouver goal. Franco Fragapane finished the sequence with a long run on the dribble until he scored in the 17th minute.

Newcomer and second-half sub Jonathan Gonzalez scored the Loons' other goal, in the 77th minute.

"When we're at our best, it's a collective," Heath said. "Everybody defends, everybody attacks and that's how it should be and how it is in the modern game. We can't afford to have two or three not quite in it. It's all connected."

Etc.

• Forward Bongokuhle Hlongwane trained for part of Tuesday's session and Heath said he's hopeful Hlongwane will participate fully Wednesday on his healing knee.

• Central midfielder Kervin Arriaga returns Monday from a one-game suspension, which Heath says gives "flexibility" to where he plays Robin Lod.