The memo appeared on the players’ phones sometime after the end of U.S. Open second-round play Friday at Shinnecock Hills.

The warning, from the desk of the USGA, read:

“For Saturday & Sunday, the golf course will be prepared to play progressively firmer and the target green speed will be 11.0 on the USGA Stimpmeter.’’

A loose translation of those words could go something like this: “OK, we’ve let everyone have their fun for the first two days and now it’s time for you to experience some suffering.’’

Dylan Wu was the first player among the 72 who made the cut to tee off Saturday at 9 a.m. off No. 1.

When he arrived at the first green of the usually benign par-4 starting hole, he five-putted and limped to the second tee with a quadruple-bogey 8.

The scene brought back memories of the great Seve Ballesteros at the 1986 Masters when he four-putted the par-3 16th green and was asked how he did it.

“I miss the putt. I miss the putt. I miss the putt. I make,” Ballesteros deadpanned.

There was some cruel irony to Wu’s five-jack on No. 1 since he’d made a clutch 7-footer for a par save on the 18th hole to close out his second round Friday to make the cut on the number, at 4 over par.

“I was super happy to make the cut — got up and down on the last hole to make it,’’ Wu said after shooting 82.

The five-putt?

“I knew the greens were sped up and thought I had a pretty good first putt and then it just turned into tic-tac-toe out there,’’ Wu said. “I was like, ‘What’s going on right now?’ It was not a fun moment.’’

That said, Wu refused to complain about the setup, instead praising the USGA, which is somewhat of a novel concept — particularly at Shinnecock for a U.S. Open.

The USGA has famously made itself a part of the U.S. Open story at Shinnecock for all the wrong reasons (see: 2004 hole No. 7 and 2018 Phil Mickelson meltdown).

If we were going to skewer the USGA for those famous faux pas — and we have — it’s only fair to praise the job it’s done this week, proceeding with prudence and caution into the week with course setup.

The first two days, with super-windy conditions in Thursday’s opening round, it set pins in the most accessible places and moved some tee boxes forward to combat the conditions. The greens were kept to 10.0 to 10.5 on the Stimpmeter the first two days to keep them as receptive as possible.

To its credit, the USGA also has been transparent all week about course setup, right down to that memo it sent the players Friday night.

“I don’t think it was too out of hand,’’ Wu said.

“I think the setup has been good,’’ Rory McIlroy said after his second round Friday. “I would say that the storyline over the first two days hasn’t really been the setup. It’s been the golf course.’’

Tommy Fleetwood, the runner-up to 2018 winner Brooks Koepka, said he was “surprised on Monday’’ to see how soft the greens were.

“The course was very, very soft and slow, but they’ve clearly judged it perfectly,’’ he said.

Neither the course nor the setup suited Irishman Shane Lowry, who missed the cut Friday.

“I’m not enjoying it,’’ Lowry said. “I didn’t have any fun this week. I find the course very hard, to be honest. It’s a very stressful golf course.”

Lowry didn’t need to tell that to Wu.

When Wu came out of scoring after his round Saturday, I asked him, “How are you doing?’’

“I’m glad it’s over,’’ he said. “I’m just looking forward to spending Father’s Day with my dad [Kevin] tomorrow and having another walk around here. Whoever wins this week is a true U.S. Open champion.”