Staker played his first game since round 23, 2011 last Saturday and kicked the match-sealing goal in the final minute.
It was the culmination of seemingly endless rehabilitation after undergoing two knee reconstructions.
McGrath said Lions co-captain Jonathan Brown used Staker's comeback as a motivational tool at several stages of the match.
It was enough to produce what coach Michael Voss described as the Lions' most significant win since the elimination final triumph against Carlton in 2009.
McGrath said it was not only a fairytale for Staker, but an inspiration to his teammates.
"It's a massive lift. It's a lonely place being in the rehab group when you have two recos in a row," McGrath said.
"I know ‘Browny’ spoke about it before the game and at half-time and even three quarter-time, just the fight to get back and play another AFL game.
"Just to see him kick the goal, you saw the boys get around him.
"To have all the emotions of that one game and to have the ball in your hands to seal the win for the boys is a big thing. If anyone could have done it, it was ‘Stakes’."
McGrath, who turned 30 on Monday, said after a disappointing opening month to the season, the Lions players got together to right the ship.
He said they showed signs over the final three quarters in a round six loss to the Sydney Swans, improved the following week in a narrow defeat to West Coast and finally hit their stride against the Bombers.
"It's just going back to basics," he said.
"We did that all through the NAB Cup, and kind of went away from that.
"All the boys got together and spoke their mind and told each other what needed to be done. We just got back to doing the simple things well, and I thought it showed on the weekend."
Michael Whiting covers Brisbane Lions news for AFL.com.au. Follow him on Twitter: @AFL_mikewhiting
