Might Apple (NASDAQ: AAPL) chief executive Tim Cook’s eyes have lit up when he learned that the vendor’s former whiz-bang head of retail head Ron Johnson had been ousted from the top spot at department store retailer J.C. Penney (NYSE: JCP) after only 18 months at the helm? Before the ink even is dry on Johnson’s exit terms, the buzz is building about what Cook and Johnson might do. Here are some possibilities ...

Apple’s retail chief job has been vacant since last October when the vendor jettisoned John Browett, its Retail senior vice president, ostensibly after he cut staffing hours at Apple’s retail stores—a blunder the vendor subsequently walked back but not far enough to save Browett's job. Who better to take over than Johnson, the architect of Apple’s stores strategy? Johnson, who left Apple in November 2011 for what was said to be a three-year to five-year turnaround effort at Penney’s, can’t be feeling too good about his mercurial foray away from Cupertino. There’s no telling if he quit or was shown the door, but in any case, his short tenure must have left him with a sour aftertaste.

Under those circumstances, who knows if he’s interested in returning to the mother ship or if Apple even will make an overture to him? Word is he’s been on good terms with the vendor since leaving. Without doubt, the old saying, “once a CEO, always a CEO,” is likely to hold here, so any idea that Johnson will return to run Apple’s retail operation, after having already built it, is unlikely. In a nutshell, he’s been there, done that.

But that doesn’t mean he might not be amenable to lending a hand. There are a number of ways Johnson and Cook might work together to continue Apple’s astounding forward momentum with its stores. For example, he might best be thought of as a “ringer,” someone brought into the fold with little formality, a lot of flexibility, significant influence, but perhaps no signing power, say as a consultant, a board member, a strategic adviser—something in that class of contributor.

What are the chances that Cook calls Johnson, if only just to chat? Let’s give this one a 10 out of 10. And, the chances that Johnson ends up working with Apple in some non-executive, non-employee capacity? That’s probably a toss-up, maybe a slight lean to yes, say 5.5 out of 10.