Saracens have tapped into the world of Gaelic football for motivation before Saturday's Champions Cup semi-final against Clermont Auvergne.
- now a sports psychologist at Scottish football club Celtic - has been in camp this week speaking to the players.
"There were some parallels in his story and ours," Saracens director of rugby Mark McCall told BBC Radio 5 live.
"We can draw some inspiration from the journey that he went on with his team."
He continued: "How they did in some of their bigger games - the semi-finals and finals - and the way they went about it.
"We bring speakers in all the time, and we thought this was a useful week for him to come in to remind the players the important things to get right this week. He spoke to the group and captivated them."
McGuinness took charge of a struggling Donegal side in 2010 before transforming them into while Saracens are looking to recover from the disappointment of losing both the Premiership and Heineken Cup finals last year.
This weekend's last-four tie in St-Etienne is a rematch of last year's semi-final, which Saracens
"It would be dangerous to look back too far and dangerous to be too spooked by what they did to Northampton two weeks ago," said McCall.
"Those things can happen in rugby. We know they are a good team with quality all over.
"I suppose all we want to do this Saturday is leave it all out there on the pitch and hold nothing back.
"I'd hate us to come away having given 85 or 90%."