Having not missed a game since round six this year, Heffernan will be forced to sit out Melbourne's elimination final against Essendon this Saturday, but would be available should the Demons advance into the second week of finals.
The former Bomber pleaded guilty to an off-the-ball felling of West Coast Eagle Daniel Chick and was found to have committed an 'unnecessary, forceful strike borne of frustration', but on a count of his good record was handed a minimum sentence.
A two-match suspension for striking in 1999 was the only prior blemish on Heffernan's 135-game, eight year career before Tuesday night's hearing.
"It might be his saving grace to some extent this evening," Tribunal chairman Brian Collis said of Heffernan's record.
Reporting umpire Dean Margetts, who was an emergency field officiator in Saturday's match at Subiaco Oval, said he had a clear view of the incident from 15 metres away and said he saw Heffernan swing a clenched fist into Chick's midriff.
"(He used his) left, clenched fist with quite a fair amount of force to the stomach, groin area," Margetts said.
Chick, who was doubled over following the contact, told the Tribunal he had felt 'medium' force to his belly button and was slightly winded after being caught unawares.
Heffernan explained that he had felt irritated after being shepherded off a previous passage of play, and then made 'incidental contact' to Chick's stomach.
"I was a bit frustrated…Instinctively I thought about throwing Daniel to the ground…but I thought the better of that," he told the tribunal.
"All I can figure (from watching the video replay) is that there's no force whatsoever. It's just pure fluke that I caught Daniel…and he's gone down winded."
"No one's more surprised than me that he's doubled over (afterwards)."
Melbourne football manager Danny Corcoran provided a character reference for the player he helped recruit from Essendon.
"He's a leader in our club. He would never, ever deliberately hurt another player…I couldn't speak highly enough of Chris," Corcoran said of Heffernan.
Chick suffered no lasting inconvenience, and though he did not play after half-time, said it was due to an unrelated matter.
