MacDonald's manager, Lex McMahon, told MMAFighting.com on Friday that talks have begun to reschedule the bout that originally was slated for Sept. 22 at UFC 152 in Toronto.
"I've been in communication with B.J.'s camp and UFC," McMahon said. "The possibility of headlining the Fox card in December is attractive as it provides a great platform to showcase the return of B.J. Penn, one of our sport's icons, as well as to introduce the mainstream fans to one of the brightest young stars in the form of Rory.
"At this juncture nothing has been agreed upon, but needless to say Rory and his team would welcome the opportunity to fight B.J. Penn on Fox in the main event."
The fight was placed on hold earlier this month when MacDonald suffered a cut above his right eye during training. More than 30 stitches were needed to close the injury.
Penn seriously considered retiring after a lopsided unanimous decision loss to Nick Diaz on Oct. 29, 2011. After softening his stance on retirement, Penn received a challenge from MacDonald and accepted it.