Reports on Thursday indicated that Manning has been cleared by his own doctors to return to football following neck surgery that kept him sidelined for the entire 2011 season.
However, Irsay responded differently on Twitter.
"Peyton has not passed our physical nor has he been cleared to play for The Indianapolis Colts," Irsay tweeted. "Team statement coming on Friday."
Last Friday, Manning and Irsay issued a joint statement in an attempt to quell rumors of a disruptive spat between the two. Both had made comments through the media earlier in the week following the upheaval in the club's front office and coaching staff.
There has been speculation that Manning, healthy or not, may not return for the Colts next season.
After a 2-14 season without the four-time MVP, the Colts gained the first pick in April's draft. With Stanford quarterback Andrew Luck considered a can't miss prospect, the team may be willing to shed Manning's high price and start over.
A March 8 deadline looms for the Colts, who must decide whether to keep Manning and pay him a $28 million roster bonus for 2012 or allow him to leave as a free agent.