The phrase "a possible comeback of" is correct and usable in written English.
It can be used when discussing the potential return or resurgence of something, such as a trend, event, or individual.
Example: "There has been much speculation about a possible comeback of the popular television series after its cancellation."
Alternatives: "a potential return of" or "a possible revival of".
Sources close to the show said no decisions had been made about the judging panel for next year after reports of a possible comeback for Cheryl Cole.
And his team seems more than willing to stoke the flames of a possible comeback and a dramatic return.
Ferguson said he had been dismayed by United's defensive record and reported "absolutely no chance" of Nemanja Vidic featuring in Sunday's derby now his captain has pulled out of a possible comeback in their Champions League tie against Cluj at Old Trafford on Wednesday.
Bartoli cited the wear and tear on her body and, after initially saying "never say never" about a possible comeback, had shot down all talk of her changing her mind.
(Both are reportedly talking to O'Reilly about a possible comeback).
Roddick insisted he was not testing the Biscayne Bay waters for a possible comeback.
But this month he told The Associated Press, when asked about a possible comeback, "You never know".
Rumors began to swirl about a possible return of "The Comeback" a few weeks ago, and on Monday HBO made it official.
There also are conflicting opinions about the best way to contain the possible comeback of Islamist extremism after two years of rule by the government of President Ibrahim Boubacar Keïta, which is widely described as democratic but sluggish and corrupt.
While Geoffrey's Toy Box is notable for marking the possible comeback of Toys R Us, it's unlikely that it'll capture much of the holiday toy market because of its limited offerings, according to Linda Bolton Weiser, an analyst with D.A. Davidson.
