In a mere minute last Sunday, Minnesota United's Lawrence Olum went from seated substitute to second-half starter in the team's scoreless tie at Portland.

That's truly about all the notice he received that center-back Ike Opara was ill and done for the day, and Olum was needed on a moment's notice.

"That's why I'm here," he said.

That's why in March United signed the veteran defender, known to his teammates as "Lo'' because of his initials.

By doing so, it reunited Olum with a Minnesota franchise and coach Adrian Heath, as well. Now 35, he played for the USL's Minnesota Thunder in 2009 and played for Heath in that same league in Austin, Texas, and Orlando.

United, which signed him because of his experience, versatility and dependability, might need some spot help to reach the playoffs for the first time in three MLS seasons.

United can clinch a playoff spot if it defeats Sporting Kansas City on Wednesday at an Allianz Field, which has sold out all season. Heath said Tuesday that he expected Opara back in his starter's spot.

A victory also would move United back into second place in the Western Conference in its pursuit of at least one home playoff game.

By signing Olum, United acquired a quiet, steady locker-room presence and its unofficial disc jockey, too.

"It's just a matter that I sit next to the boom box, and it has the controls," said Olum, a former Kenyan national team member.

Backup center-back Brent Kallman's 10-game suspension, which stretches into next season, and Opara's health Sunday created a need for Olum to come in on short notice after young center back Wyatt Omsberg warmed up before halftime.

"Obviously, Lo's class," United defender Michael Boxall said. "He has shown that for a handful of games this season. Whenever thrown into whatever position he has had to fill for us, he has done a class job. That's full credit to him for the work he has done and the work he has done throughout his career."

Heath said he went with Olum Sunday because of his experience. In the past two seasons, Olum reached the 2018 MLS Cup final with Portland. Five seasons before that, he played for Sporting K.C. when it won the 2013 championship.

His ability to play both defensive midfield and center back didn't hurt, either.

"He's really good in both boxes, as well," Heath said. "When Lo plays back there — because he is used to playing in the thick of it in midfield — he does bring a calmness. He's used to not playing with a lot of space around him. It's normally harem-scarem where he is. So he does give you a real nice air of confidence and calmness when he's on the ball."

Olum did so Sunday on that minute's notice. That, of course, is why he's there.

"All week I had been training for that," Olum said. "Adrian's the coach. He makes those calls and he called me up and I was ready."

It's a veteran's job, just as Olum's other role is to unify an Allianz Field locker room before and after games with rhythm and sound. As DJ, he plays everything from world music and old-school Queen to the motion-picture "Ghostbusters" theme released the year he was born, 1984.

"Usually guys ask for a little of everything from around the world because we've got a diverse locker room," Olum said. "I'm a reggae person myself, but the young guys, they teach me stuff and I teach them stuff. If they didn't know it before, they do now."