Apple could unveil the 'holy grail': Sculley

Mobile payments today's sleeper: John Sculley
Mobile payments today's sleeper: John Sculley

Apple will likely unveil mobile payments on Tuesday, "the holy grail for e-commerce" and a "game-changing product" that could revolutionize the entire industry, former CEO John Sculley told CNBC.

People sit in front of an Apple store in New York on September 9, 2014.
Carlo Allegri | CNBC

Sculley, who appeared on "Squawk on the Street" before the Apple event, said the technology giant has long "been putting together the pieces" for a mobile payments product.

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"The most important piece are 800 million credit-card-scored iPhone users," Sculley said. "And when you combine that with OneTouch for the biometric security, combine that with [near field communication], which is also high security, and tie it in the announcements, which Apple has said they're going to make with the major credit card companies, major retailers, I think we're in for something that's going really game-changing."

Aside from company executives and a few employees, nobody knows exactly what the tech behemoth will announce, but that hasn't stopped Apple observers from speculating.

Many think Apple will reveal the new iPhone 6 with both 4.7-inch and 5.5-inch screens—bigger than the 4-inch screen on the iPhone 5s and 5c. Others are expecting an iWatch.

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To Sculley, who ran Apple from 1983 to 1993, the company will likely announce the iPhone 6. The latest generation smartphone will be "phenomenal," but he doesn't think it will wow users because it's "already a well understood product." People are hungry for a "creative leap" that mobile payments will provide, he said.

—By CNBC's Drew Sandholm.