But even when a dream job as a strength and conditioning expert with a professional soccer team in the UK came up last August, the Ballymun man felt he had to turn it down.
Dublin was the priority.
To be precise, his desire to win an All-Ireland medal as a fully functioning regular from the beginning of the championship to the end of September was ultimately what kept him here.
It’s a case of so far, so good in this year’s championship. The former Shamrock Rovers strength and conditioning coach has started every game for Dublin and looks set to play a key role again in a full-back line detailed to shackle Mayo’s danger man Aidan O’Shea in Sunday’s All-Ireland semi-final. The offer to jack it all in and focus on a career he loves was tempting all the same for the 28-year old personal trainer who already has various professional soccer clients on his books, including Manchester City’s teenage sensation Jack Byrne.
“I was asked to go over to a club last season but I couldn’t because they start pre-season in August and we were still in the championship at that stage here,” said McMahon.
“It’s something I’d probably like to do eventually. It was basically down to that, we were still playing so I couldn’t get over.
“I offered to be a consultant but I wasn’t able to give them enough time - they wanted somebody full-time.” McMahon described his experience with the English club as an eye-opener as he compared and contrasted their physical preparations and recovery activities with those employed by top county set-ups here.
“It was interesting to see when I met with the manager how much they were actually missing out on,” said McMahon, an AIB All-Ireland club finalist with Ballymun Kickhams in 2013.
“When you think of England, you think they must be miles ahead of what we have here in Ireland but they’re actually missing out on a lot.”
Asked which he would choose if he was beginning his sporting career again, soccer in England or unpaid Gaelic football in Ireland, he said there was no contest.
“GAA by a mile because we’re building a career now during our sporting years whereas I’ve dealt with a lot of players who have been professional soccer players and they don’t know what to do afterwards,” said McMahon.
“They don’t think about anything after their sporting days. All these kids think of is money, there and then.
“They initially love the sport but eventually contracts come into play, money comes into play, and they think they’re going to be on money that Ronaldo is on but no, they’re not.
“Unfortunately, we haven’t in the last 20 years produced a player that earns the money Ronaldo earns. Robbie Keane might make a few quid but it’s a lot lower than Ronaldo gets.”
Jim McGuinness, the All-Ireland winning Donegal manager of 2012, is employed by Glasgow Celtic as a performance coach while Barry Solan, Mayo’s strength and conditioning coach, has recently joined Arsenal’s team of fitness experts.
“Sport is getting very professional at the minute so other codes might come in and go, ‘What are they doing in the GAA that we can bring into our sport?’ said McMahon. “I do think our amateur status, combined with the professional level that we’re playing and training at and committing to is something they could look at on the soccer side of things in England.”
McMahon said he ultimately hopes to advance his career in England when his GAA career is over though, for now, it’s all about overcoming the challenge of Mayo this weekend and qualifying for his third All-Ireland final.
The martial arts enthusiast insisted the memory of last year’s painful defeat to Donegal at this stage doesn’t act as any extra motivation approaching the clash with five-in-a-row Connacht champions Mayo.
“There’s hunger every year because you’ve only got 10 to 13 years of playing football,” says McMahon. “I’ve played seven or eight seasons now and haven’t had that full season (in the team) to win an All-Ireland. That’s where the hunger is for me. There’s hunger for other players who haven’t played as much is to be involved, so it depends on your individual goals. But you do naturally want to win as much as you can in your career and every year when you get a chance to put that jersey on, you want to win that bit of tin as badly as ever.”