Nike (NKE) might have a Foot Locker (FL) problem.

After Foot Locker slashed its full-year sales forecast amid what it described as a "tough macroeconomic backdrop,” there is growing concern on Wall Street that Nike may also be caught in the crosshairs.

“We are reducing NIKE estimates to reflect indications of slowing U.S. consumer spend and U.S. athletic footwear channel inventory imbalances,” Stifel analyst Jim Duffy wrote in a note to clients. “Foot Locker results, commentary, and outlook highlight headwinds.”

Foot Locker’s first-quarter release before the bell on Friday has sent the stock tumbling more than 30% through two trading sessions. It highlighted declining same-store sales that couldsink as much as 9% this year and “higher than average” inventories in the first quarter.

Nike accounts for more than 70% of Foot Locker’s sales and is now seeing its stock drop on Foot Locker's print, with shares down nearly 3% on Monday.

Foot Locker reported non-Nike penetration increasing to 35% in the first quarter, which equates to mid teens decreases for Nike sales, largely driven by weakness in lifestyle running, per Wedbush securities analyst Tom Nikic.

But it's not just about the performance last quarter. On a call with investors on Friday, Foot Locker referenced clearing inventory and increasing promotions through the end of the year to eventually bring newness to its stores.

With sporting goods recently having beenthe worst performing segment in monthly retail sales, Foot Locker’s outlook has cast a shadow over demand in the sector. In a note titled “opening downside 90-day catalyst watch,” Citi analyst Paul Lejuez wrote a consumer slowdown and inventory overhang in the North American athletic apparel market reflects poorly on Nike’s fiscal-year expectations.

“Given the seemingly high inventory levels in the channel (in footwear in particular) following a pullback in spending from lower income consumers, we believe the margin setup may not be as favorable as previously thought,” Lejueze wrote.