Loons goalkeeper Bobby Shuttleworth made a save off a corner kick againt Houston on April 28. But opponents have been more successful on set pieces against the Loons of late, scoring five times over their past six games. (The Minnesota Star Tribune)

Whenever Minnesota United steps up for a corner kick at TCF Bank Stadium, the 20,000 or so in attendance stand and whip their soccer scarves around above their heads. It's one of the hallmarks of the gameday atmosphere, and a tradition likely to continue for years to come.

But at least so far this season, that extra motivation hasn't helped the Loons come out on top.

Ahead of United facing Real Salt Lake on Saturday night at TCF Bank Stadium, the Loons have earned 91 corner kicks in 21 matches this season while conceding 113, including the two U.S. Open Cup matches and the international friendly earlier this week. The Loons have yet to score a goal from a set piece — dead-ball situations such as direct free kicks and corners. But United has allowed one free-kick goal and seven corner-kick goals, including five in the past six games.

Those statistics have assistant coach Mark Watson, who leads the defensive efforts, quantifying the frustration level as "high," which he said might even be an understatement.

"It's obviously a big area of concern, especially recently just because of the number of goals we have conceded, and the goals have cost us points," Watson said. "The World Cup is a great example of just how important set pieces are. They've decided games on many occasions. … For us, it's overshadowing a lot of really good performances. And it's something that can't continue."

According to FIFA.com, 42 percent of this World Cup's goals this summer have come from set pieces. That's 68 set-piece goals in 62 games, a record that tops the 62 scored in France in 1998.

That is some solace for coach Adrian Heath. He pointed to Belgium, a team that had seven players 6-3 or taller but still lost out on the World Cup final after losing to France by one corner-kick header from a 6-foot player.

"Everybody's an expert on set pieces," Heath said. "Sometimes it's about the delivery. Sometimes it's about the desire. Is it zonal [marking]? Is it man-for-man? Is it a mixture? Everybody's tried it. … People spend a lot of time on them now, and at this moment in time, we've been caught out with it. And we have to address it. But is there a simple answer to it? No."

Defense-wise, Watson said the main problem is mentality. United has mainly executed man-to-man marking on set pieces, but for every corner kick goal conceded, it's a different player making the mistake. Such players as Brent Kallman, Marc Burch, Francisco Calvo, Ibson, Rasmus Schuller, Tyrone Mears, Collin Martin, Wyatt Omsberg, Collen Warner and Michael Boxall have all shouldered some responsibility for allowing set-piece goals this year.

"Man-to-man marking, you have a player that you mark, and your player doesn't score," Watson said. "It's willing to fight through a lot of little things, hands and pushes and bumps and picks. But that's the job, and we haven't done a good enough job of it."

Attacking-wise, Heath said sometimes the problem is not having enough quality going into the box, though he thinks his team has improved on that in the past few weeks. Kallman said the squad needs to do a better job of not hitting the ball directly at the goalkeeper and making opponents fight for clearances. Forward Christian Ramirez said the players need to continue to make runs into the box and not become frustrated when the ball doesn't fall to them.

Sporting director Manny Lagos said in a season-ticket holder teleconference Friday that he expects players like Kallman, Calvo and Boxall to have a couple of goals a year from set-piece headers.

"We've tried to put different people on the set pieces to help out with it. I still think that this staff is really working to push our good headers … to really think about how they're creating more space and getting free," Lagos said. "We've thought about hitting one short and then serving a man. We've thought about who really hits them to what spaces. Again, they're working very hard at identifying how people are playing. Are they zone match with us, one-v.-one? And at the end of the day, my answer is yes, we have to get better. We have to get production out of our set pieces."

The Loons have worked on several changes this week for attacking and defending set pieces, and those will likely debut against Salt Lake on Saturday.

"We can't carry on as we are," Heath said. "We have to change something."