Scully was labelled a draft 'bust' in a newspaper article leading into Saturday's match against Essendon, having failed so far to fulfil the lofty expectations that come with being a No.1 draft pick.
It's not the the first time the 21-year-old had been criticised in his 56-game career after he left Melbourne to join GWS on a lucrative contract at the end of 2011.
For a half on Saturday the midfielder answered his critics, winning 14 possessions and kicking two goals to half-time against the Bombers to drive his team's stunning early surge.
He faded in the second half, but Sheedy's defence of his young on-ball leader was emphatic following the Giants' 39-point loss at Etihad Stadium.
"I think Tom Scully's a very courageous young man," he said.
"I don't think he needs to be shown the headline. I think they're embedded in his brain.
"This guy will work through it and it will steel him for being a wonderful player for the Giants within two years. When he's starting to rack up 90-100 games, look out.
"I just keep telling him, 'Suck it in mate because one day you're going to be a champion'."
Scully was perhaps the most influential player on the ground in the first half on Saturday, having also restricted in-form opponent Brent Stanton to just eight disposals.
Key forward Jeremy Cameron, who kicked four first-half goals and finished with a club-record six, was his main competition.
Cameron said the Giants' players had been motivated by pre-game talk that Saturday's match was effectively the Bombers' bye.
"We knew coming into the game that we could put our best foot forward," he said.
"'Sheeds' and the coaches wanted us to start well and we came out firing. I thought our first half was probably the best half we've played.
"We showed a lot of spirit in the first half and later in the game as well.
"When Essendon kicked a few goals, we really dug in deep and got a few back."
Jacob Townsend was another young Giant who stood up to the Bombers on Saturday, running with Brownlow medallist Jobe Watson and restricting him to eight first-half possessions and one clearance.
With Tim Mohr, Taylor Adams, Adam Treloar and Aidan Corr others to impress, Sheedy said his team would take confidence into their first match for the season at Skoda Stadium, against Adelaide next Sunday.
"I reckon we're a chance next week," he said.
"If we play like this for the whole game next week, we're a chance.
"We let them (Essendon) off the hook in the third quarter a little bit.
"It'd be nice to be ahead of a top team around three-quarter time with a half-hour zone to work through.
"I think that's where we're at and what we've got to do."
Nathan Schmook is a reporter for AFL Media. Follow him on Twitter: @AFL_Nathan
