On Wednesday, the eve of the Northern Trust at Liberty National, Dan Fireman, the president of the club and son of its founder, Paul Fireman, was asked what he’d like the winning score to be this week.

He joked about how his old-school dad would probably prefer it not to be very far under par.

Well, with Wednesday’s heavy rain softening the course and virtually no wind during Thursday’s opening round, the Firemans did not get their wish. The players ate Liberty National for lunch Thursday, with the leaderboards bleeding with red numbers signifying many under-par scores.

Eighty of the 120-player field posted rounds below par.

Troy Merritt’s 9-under-par 62 led the way, with Dustin Johnson’s 63 right behind, followed by 63s by Jon Rahm and Kevin Kisner. Rory McIlroy, Tony Finau, Webb Simpson, and Justin Rose all posted 6-under-par 65s.

“We were wondering how the course would hold up [Wednesday] night, and it was nice and soft out there,’’ Merritt said. “The greens were real receptive, and they were rolling beautiful this morning. You just had to get it on line at the proper pace, and it was going in.’’

The course seemed easy for almost everyone on the field except for Tiger Woods, who shot a 4-over-par 75 and is tied for 117th. Only one player, Patrick Rodgers, posted a higher score than Woods, with a 5-over-par 76.

McIlroy recalled watching the Presidents Cup two years ago and salivating at the thought of playing Liberty National.

“I watched the Presidents Cup here a couple of years ago and I guess they got the course really firm that week, and that looked really fun to play,’’ he said. “I think this course could be fun playing it that way [firm], but you have to take what you get. This week, we’ve gotten a soft golf course and just try to play it the best we can. There’s not much rough out there, so it’s sort of bombs away with the driver and try to get it up as far as you can and go from there.

“It’s definitely a golf course that you’re going to have to keep being aggressive on this week.’’

Rahm said he believes the course “favors the long hitter,’’ which makes sense when you see the likes of him, Johnson, McIlroy and Finau at the top of the leaderboard.

“The rough is not very thick,’’ Rahm said. “We were pretty aggressive off the tee, and you start taking certain lines and hitting drivers everywhere, with a little bit of like a loose attitude knowing that if you miss a couple shots and still have a chance with the rough, it helps out.

“I don’t know if it’s coincidence or the fact that it’s toward the end of the season and all the guys that are playing good are still just keeping a good run going.’’

Rahm’s group — he played with Simpson and Johnson — was a combined 21-under par.

“Everything looked easy and we fed off each other,’’ he said. “One of us was always close and we were trying to get it closer than the next person and making putts. There was a good vibe in the group going on. The only reason why I think it’s possible it’s a little bit easier is because the greens are so soft.’’

For Merritt, the leader, staying at or near the top of the board is particularly paramount considering he entered the week No. 72 in the FedExCup points standings and only the top 70 advance to the BMW Championship next week.

“I didn’t think about it a whole lot,’’ Merritt said of his standing. “I know good golf will take care of itself. You just try to play the best you can. Obviously be watching throughout the weekend, but just getting off to a good start, put that to the back of the mind and try to win a golf tournament and do that, I’ll get inside the top 70.’’