While Apple's head of operations, Jeff Williams, has called the response to the Apple Watch "fantastic," analyst Alex Gauna said the wearable's debut has been "less than spectacular."
Williams' comments came during the second annual Code Conference in Rancho Palos Verdes, California, on Wednesday. However, he would not cite specific numbers.
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While analysts at JPMorgan are predicting the tech giant will sell 36 million watches in the first 12 months, Guana thinks the figure is closer to 15 million.
"What we have is sources in the supply chain that suggest there were supply constraints as we started the ramp of this and then we're not yet in holiday season," the senior analyst at JMP Securities said in an interview with CNBC's "Closing Bell."
"We think that's why there's been a rather lackluster start to the Apple Watch sales."
However, he thinks the watch is a stepping stone for greater "Internet of Things" aspirations and believes future generations of the device will have the features and battery life it needs to be compelling.
Despite his lack of enthusiasm for the Apple Watch at the moment, he's still bullish on the stock.
"I don't think that the Apple Watch is central to Apple investment proposition," he said, noting that the iPhone 6 and iPhone 6 Plus continue to be "runaway hits."
Meanwhile, Amish Shah, managing director of Sierra Maya 360, called the watch another groundbreaking ecosystem.
"Apple is a way of life," he said.
He also thinks the third-party apps for the Apple Watch are going to open up more towards the end of the year.
"This is going to open up all these companies and all these businesses that didn't exist," said Shah.
—CNBC's Josh Lipton contributed to this report.
Disclosures: JMP Securities currently makes a market in Apple. JMP Securities expects to receive OR intends to seek compensation for investment banking services from the subject company in the next three months. Amish Shah and his family personal own shares of Apple; his firm does not own shares.