Major League Soccer on Thursday suspended Minnesota United veteran defender Brent Kallman for 10 games and fined him for violating the league's substance-abuse and behavioral-health policy.

Kallman told reporters he takes responsibility for a product he took for about four weeks over the summer. He said he thought it would help him hasten his recovery from what he called a "rough spot" with injuries and get him back to full fitness more quickly.

"That's where I gave in and I caved to the pressure and I started taking something," Kallman said. "And now I'm paying the consequences for it."

The suspension will include the four remaining regular-season games for the Loons, who are battling for a playoff spot, and any postseason games United might play. It also will stretch into the 2020 regular season.

He'll also be fined 20% of his annual salary, which includes a base of $118,000 and $136,456 total compensation in 2019.

Kallman, who grew up in Woodbury, apologized on his social-media accounts to family, friends, supporters, teammates past and present, coaches, MLS and its players for what he called a "careless, selfish decision" he made without consulting with the team's training staff.

He declined to say what the product or its substances were.

Kallman will be banned from team training, team training facilities, games and events until United's season ends, unless it's supervised injury rehabilitation.

He'll be allowed to participate in preseason training next year but may not participate in any other preseason team activities.

"I'm really disappointed, disappointed in myself," he said in a brief interview Thursday. "I really feel like I let the team down. Everybody knows it's a super important push that we have going on right now, and I should be available to play if called upon. But also, I should be out there every day pushing the guys in training. The fact I can't is the most disappointing part."

Kallman, 28, addressed his teammates after training Thursday and said he'd tell them "the truth."

With the team making several offseason moves to shore up its defense, Kallman's playing time has dropped this season. In 2017, he started in all 23 games he appeared in. Last season he had 22 starts in 24 games. This year he appeared in 16 of the team's 30 MLS games and started in 14 of them.

United coach Adrian Heath said it could be six or seven months before Kallman's suspension is served and the bans lifted. He said he'll call upon such players as prospect Wyatt Omsberg or veteran Lawrence Olum if the team's depth at center back becomes an issue.

Heath also said he reminded his players to seek the team's medical staff if they reach an injury situation such as Kallman's.

"It's a disappointment, but nobody's more disappointed than the kid and hopefully it will be a cautionary tale for everybody else," Heath said. "Hopefully, people will think twice if it's ever gone through their mind. … He knew what he was doing was wrong. The shortcut route that he thought it was going to be, well, guess what? It's not so short after all."

Kallman attended Woodbury High School and played collegiately at Creighton in Omaha. He signed with Minnesota United in 2013, when it played in the North American Soccer League. He was one of six players from the final NASL team roster to sign after the club was awarded an MLS franchise beginning in 2017.

Kallman said he "asked the questions" about an appeal but didn't make one after a second sample tested turned out positive.

"They make you aware when you have your meetings that you're responsible for what you put in your body," he said. "It didn't seem like it would go anywhere."

He said he wanted to apologize personally to his teammates.

"To apologize for not being there for them and that it could be seen as a distraction," he said. "Give them my encouragement to try the best not to let it be and to take care of business and see the season out well."

Minnesota United defender Brent Kallman will miss the rest of the season on suspension. (The Minnesota Star Tribune)