The Easter Road outfit travel north to Pittodrie for a League rematch just two months after the converted winger-striker stole three points for the Dons with the only goal in Edinburgh.
Northern Ireland international McGinn now has 16 strikes to his name but Fenlon insists the threat will come from the entire Reds attack, rather than one man alone.
And similarly, he does not expect Aberdeen boss Craig Brown to come up with anything spectacular to nullify the threat of his own 15-goal poacher Leigh Griffiths.
Fenlon told Press Association Sport: "Both sides have scored plenty of goals.
"McGinn has grabbed a load for Aberdeen and Leigh has obviously scored a fair few for us. And we have also had Eoin Doyle chipping in with a few too.
"Aberdeen are an attack-minded team and the games we have played have been decent matches for people to watch.
"But we won't go in with a special plan to stop just one player. Our game plan is to play as a team and to try and nullify the threats we think they have, and then exploit the areas that we think we can hurt them.
"They will be in the same situation, so it will be about how the teams perform rather than the individuals."
Fenlon could barely hide his disappointment following November's narrow defeat to the Reds at Easter Road after the match.
The loss cost them the chance to climb above Celtic at the top of the SPL summit and, since then, just two wins have been picked up in the eight subsequent league fixtures.
However, the Leith boss is not worried.
"I'm more than happy with the way things have gone since then. We've had a couple of hiccups but we have played quite well," said Fenlon.
"Our aspirations at that point (of the Aberdeen match) were not to be top of the table but to win football matches.
"The league is so tight that everyone is in the same situation. If you can get a run of four or five wins on the spin, it will take you into a real good situation."