Kevin Plank broke Under Armour. Can he fix it?

“My top priority is to bring clarity and stability to our business," he told investors in May, when Plank also warned them that the company’s sales would drop at least 10% this year.

The 52-year-old billionaire had never left the company he started nearly 30 years ago. After stepping aside as CEO in late 2019, he stayed on as executive chairman and brand chief. And he remained the controlling shareholder, thanks to supervoting shares.

More than half a dozen former executives said Plank was responsible for much of the turmoil and complexity that he is now promising to clean up. In recent years, they say he foiled marketing plans put in place by others, he pushed product ideas that flopped and blurred the lines between his brand role and that of the CEOs that succeeded him.

Much like Bob Iger at Disney and Howard Schultz at Starbucks who were reinstated as CEO, Plank and the Under Armour board have decided that the business he long ran needs a rescue and he is the best person to pull it off.

“Under Armour continues to address what has distracted us from our core mission," a company spokesman said. “Under Kevin’s leadership, we are determined to change the trajectory of this business."

Under Armour said Plank and the board supported the CEOs who were selected to succeed him and they had the opportunity to do so how they saw fit. Plank “continued to have a founder’s opinion on the business he built, particularly in the areas of brand marketing, product, and innovation," the spokesman said.

BlackBerry fears

Plank is betting that the company can become a premium sports brand by cutting the number of products it sells by 25%, reducing the discounts it offers and delivering more impactful merchandise. His plan is to reconstitute a brand that has lost its grip on shoppers after its explosive sales growth hit a wall in 2017.

Some investors and former executives doubt whether Plank’s strategy to turn the company around will make a difference for a brand that watered down its value they said by selling much of its inventory at a discount to hit revenue targets. Under Armour risks following the path of BlackBerry, a cautionary tale Plank used in meetings about an industry leader that became irrelevant, former executives said.

Shares of Under Armour have fallen 23% over the past year and are down 87% from their 2015 high, erasing $18 billion of market value. The slide began during Plank’s first CEO tenure when sales started declining in its core North American market and the company underwent three rounds of restructurings, resulting in about $1 billion in charges.

This week, the company warned of a deeper-than-expected annual loss amid higher restructuring charges, including for closing a California distribution facility that Plank opened during his first CEO stint.

The Baltimore-based company is no longer the threat it was a decade ago to giants such as Nike and Adidas. Plank has recently called it a “podium brand," meaning one of three or four global athletic brands recognized worldwide. But in an increasingly fragmented market, brands such as Skechers, New Balance, Puma and Lululemon all netted higher sales last year.

Under Armour has since 2020 consistently been the No. 1 brand that upper-income male teens say they no longer wear in a semiannual survey conducted by investment bank Piper Sandler. “We continue to believe that Under Armour has lost relevancy with its target demographic," the analysts who conducted the survey said in their report this year.

Two pitbulls

Plank shifted from CEO to brand chief, a newly created role, in late 2019 in what he said was a plan to elevate his top deputy, Patrik Frisk, as his successor. The change came in the midst of a restructuring effort to cut costs and revive sales.

The Journal reported that employees had also made complaints about Under Armour’s workplace culture and that the board had questioned Plank about his ties to TV journalist Stephanie Ruhle. Plank replaced some senior executives, said Ruhle was a friend and vowed to improve Under Armour’s culture.

After the handoff, former employees and executives said Plank showed up to product and marketing meetings, and questioned the directions they were taking despite not holding the CEO title. The billionaire’s management style is throwing two pitbulls in a room and seeing which one makes it out alive, several of them said.

Frisk, who had joined Under Armour in 2017 as president, took the CEO job after Plank agreed to attend regular sessions with an executive coach, the corporate equivalent of a couples counselor, some former executives said. Frisk hoped the therapy would keep the founder on the sidelines, they said.

Frisk created a Special Teams unit, a group that worked directly with Plank on his ideas to try to keep the founder out of day-to-day operations, executives said. Soon, Plank’s creations such as a Sportsmask during Covid and the SlipSpeed sneaker—a shoe with a collapsible heel—were prioritized over Frisk’s plans, including a focus on sustainability projects.

Some, including Plank, felt Frisk’s consultant-led style was killing the brand’s cool. Others thought Frisk brought much-needed discipline to a company that was constantly changing direction. Tensions between the two led to Frisk’s departure in mid-2022, former executives said.

Plank came up with the idea for the SlipSpeed, which can be worn for running or as a slip-on, after watching how his daughter stepped on the heel of her shoes. He called it Under Armour’s “Croc-killer"—after seeing the success the foam clog brand had with young shoppers during the early years of the pandemic.

In late 2021, product teams fast tracked Plank’s sneaker idea to deliver the product in half the usual two-year development process, sidestepping regular testing, redesigns and consumer insights. The marketing budget for the SlipSpeed dwarfed that of other launches at the company and included a pop-up store in New York City in early 2023.

“This $150 game-changing innovation with a design that is on point and is being authentically adopted by athletes everywhere," Plank said during a call with analysts in mid 2023. “UA SlipSpeed is working."

Plank told staff that he expected the SlipSpeed would be Under Armour’s most successful product yet and said it would rival Nike’s Pegasus running shoe, former executives said. The company made a big push for the shoe, but it hasn’t caught on. Prices for some of the sneaker’s newest iteration, SlipSpeed Mega, have been halved by the company’s biggest retail partners.

Executing orders

By early 2023, Under Armour had found its next leader. Plank introduced former Marriott President Stephanie Linnartz as the new CEO at the cafeteria inside its Baltimore headquarters.

Plank still ran the show even when he no longer held the CEO title, former executives said. In fact, he kept the same office he had as CEO—the biggest in the building.

In May 2023, in a call with analysts, Linnartz presented her three-year strategy to reignite growth for Under Armour. Her plan was to lean on its lifestyle products to generate more brand awareness, especially in the U.S.

“We are bringing in sneaker and branding experts who will add industry-proven design horsepower to the team, especially as we expand our Sportstyle offerings," Linnartz said during the call.

Some people at Under Armour said they realized Linnartz wasn’t the right fit. She wanted to change the way the industry was run and imposed some discipline on operations. Her moves rankled some workers who thought of her as a drill sergeant, former executives said.

Linnartz told staffers that there was a missed opportunity in making better products for women, who she said would be buying the products for themselves and their families. In meetings with designers, Linnartz said she didn’t like the company’s women’s merchandise, former employees said.

Annual sales declined 3.4% in its most recent fiscal year, and the company projected lower demand from retailers. About a year after Linnartz joined, she was out.

Now as CEO again, Plank is undoing some of his predecessors’ moves. He has vowed to cut out consultants that were prominent during Frisk’s tenure and has said the company will focus on performance products.

Some of his fix-it strategy echoes what other leaders attempted. Frisk had already worked on pulling back on discounts. Linnartz had also talked about trying to become a premium brand, trying out new store formats and having better storytelling for the products.

Write to Inti Pacheco at inti.pacheco@wsj.com