A 27-year-old American seeking his first major championship versus a 28-year-old Irishman chasing golf history.
Reed and McIlroy are forever linked to that Ryder Cup singles match at Hazeltine two years ago, which Reed won on the 18th hole. The personalities are unchanged. The events, and the stakes, are entirely different.
The crowd figures to be equally loud, just not as obnoxious.
"There's a lot of stuff that you can do at a Ryder Cup that you can't do at Augusta National," Reed said with a smile.
Don't look for McIlroy to cup his hand over his ear to encourage the gallery to scream even louder. Or for Reed to point at McIlroy if he pulls off a clutch moment.
Besides, it's stroke play. Reed has a three-shot lead. And it isn't just about them.
"It's definitely not a two-horse race at this point," McIlroy cautioned. "There's a lot more guys. I told myself today, leaderboards are huge here; it's hard to miss them. But I said to myself, 'Don't concentrate on them too much. Try not to look at them.' It's hard not to.
"I'll obviously know what Patrick Reed is doing, but apart from that, I'm going to set myself a target, try to get to that and hopefully it's enough."
McIlroy should hope he hasn't used up all his luck. He shot a 7-under 65 in the third round Saturday to match his lowest score at the Masters, pushing him within three shots of Reed and into the final pairing.
He holed a pitch shot from 23 yards for an eagle at the par-5 eighth. He saved par at the 13th after knocking his ball into a thick patch of pink azaleas. McIlroy watched an errant tee shot at the final hole ricochet back into the fairway, setting up a birdie that could have easily been a bogey.
"I rode my luck a little bit out there,” McIlroy said. "Hopefully I don't have to rely on it too much" Sunday.
This is the fourth straight year that McIlroy arrived at Augusta National looking to complete the career Grand Slam — a feat accomplished by only five of the game's greatest players.
The last three times, he was simply too far back to make a Sunday run at the green jacket.
This time, it's within reach, though he'll have to chase down a guy who's carded three straight rounds in the 60s.
"I feel like all the pressure is on him," McIlroy said. "He's got that to deal with and sleep on (Saturday night)."
Reed surely will bank on more par-5 dominance. He's played the course's longest holes at 13 under this week, better than anyone else in the field.
Reed ran off three straight birdies around the turn and stretched his lead with two eagles on the back nine.
Keeping it won't be easy, not on this stage. Reed also doesn't buy into the idea that the pressure is all on him, a notion McIlroy quickly suggested.
"I am leading," he said. "At the same time, he's going for the career Grand Slam."