Sources familiar with Manning's medical condition said the Colts QB will be re-evaluated by several doctors because of slow progress, but no other procedures are currently planned, according to ESPN's Chris Mortensen.
The Twitter world was buzzing throughout Sunday after a report surfaced that Manning would require another procedure that would keep him sidelined indefinitely.
John Michael Vincent of ESPN 1070 in Indianapolis, who said in a follow-up tweet that "he's not trying to be a newsbreaker," tweeted that news about Manning on Sunday evening.
"Been told by multi sources that QB P Manning needs a 2nd neck procedure. Will remain out indefinitely.Called #colts and waiting on response," he tweeted.
Vincent's report was met with skepticism by concerned Colts fans, though, especially after Sports Illustrated's Peter King reported that Colts president Bill Polian was unaware of such a development.
King then followed up shortly thereafter by saying that he's starting to believe Manning won't be ready to play in the season opener against the Houston Texans next Sunday.
Manning has been sidelined since May after having surgery to repair a bulging disc. He was activated off the physically unable to perform (PUP) list and was reportedly cleared to begin practicing.
If Manning is unable to start in Week 1, either recently signed veteran Kerry Collins or Curtis Painter will get the nod.