By Katie Marsal

Published: 01:00 PM EST

Piper Jaffray analyst Gene Munster, one of the most outspoken figures on all things Apple, told clients on Wednesday that Steve Jobs' absence from this year's Macworld Expo signals "the beginning of a shift in leadership roles" at the company.

"Steve Jobs remains CEO of Apple, however, yielding this year's Macworld keynote to Phil Schiller, along with the participation of Tim Cook and Phil Schiller at the October event is, in our view, a clear message that a leadership shift is underway," he said.

In addition, Jobs' decision not to deliver his high-profile speech has rekindled speculation on the part of some industry watchers and investors that his health may be deteriorating -- a scare which has sent Apple shares into a mini spiral, shedding more than 7 percent of their value since the news became public.

The Apple co-founder is a cancer surviver, having undergone successful surgery in 2004 to remove a malignant tumor from his pancreas. His company, however, remained secretive about the matter until the operation was complete and he was forced to take a leave from his daily duties as chief executive.

While Munster believes that Apple could have easily diffused speculation over its leader's health by having him keynote next month's expo, he doesn't believe the move is necessarily a sign Jobs' condition has taken a turn for the worse. However, "we do believe that it is a sign that we are in the early stages of changing roles in Apple's management structure," he told clients.

Like many Apple watchers, the analyst acknowledged that Jobs is the "irreplaceable face of Apple." That said, he argues that the company's product innovation has come from an entire organization of dedicated people spearheaded by an executive team "who share a collective track record of consistently outpacing their competitors in terms of hardware and software innovation coupled with robust product marketing and financial discipline."

"We believe that Apple's executive team is one of its competitive advantages," he added. "This management team, along with Steve Jobs, has been responsible for Apple's product innovation."

With Phil Schiller delivering this year's Macworld keynote, Munster and his team are no longer expecting the event to reveal any revolutionary products. Some remaining possibilities may include an updated iMac or redesigned Mac mini, he said.

"We continue to expect a new form factor iPhone in the March quarter," the analyst told clients. "We initially thought there was an outside chance that a new iPhone could be announced at Macworld, the news regarding the keynote leads us to believe that a new iPhone at Macworld is less likely.