Under Armour's stocked fell by more than four percent on Friday as the latest Stephen Curry shoe hasn't sold as well as expected.

Foot Locker CEO Dick Johnson said the Curry 3 "started off a bit slower than the previous models," causing a sell-off in the stock market.

Curry's products make up about five percent of Under Armour's total business.

Johnson said the basketball shoe market was softer than in the past overall.

Johnson also said it's still "early days" to completely judge the Curry 3. As of Tuesday, the Curry 3 has will have been on sale for a month.

"We're optimistic that they [Under Armour] are going to be able to continue to keep that [footwear business] with some momentum behind it and certainly expand their footwear offerings," Johnson said.