It wasn’t the best draw, but the American men’s contingent underwhelmed at the U.S. Open with more than their usual mediocrity.

When the second week of the Open began, Monday’s Labor Day card was bereft of any American men for the first time since 2014.

The last U.S. men standing were 14th-ranked John Isner and Tennys Sandgren, and both were eliminated by seeded players in the third round over the weekend.

Isner had the misfortune of facing dangerous 2014 Open champion Marin Cilic, the No. 22 seed, and lost in four sets, though he actually won more points. Isner, who still leads the tournament in aces with 91, has been playing catch-up since fracturing his foot in Miami in March.

Sandgren got bounced Saturday in the third round by No. 20 Diego Schwartzman, who is on his way to the quarterfinals after upsetting No. 6 Alexander Zverev.

The spate of first-round ousters was most troubling as arguably the top prospect, No. 24 Taylor Fritz, fell in a four-setter to Feliciano Lopez.

Sam Querrey, who has reached a Grand Slam semifinal in his career, was bounced in Round 1 along with Jack Sock and Steve Johnson.

Young U.S. prospects Frances Tiafoe and Reilly Opelka got to the second round. Tiafoe also had a miserable draw, getting Cilic in Round 2.

Opelka arguably staged the best showing, beating No. 11 seed Fabio Fognini in the opening round.

An American man hasn’t won a Grand Slam since Andy Roddick’s U.S. Open title in 2003 and there appears to be no end to the drought in sight.

By contrast, the American women keep making waves. Four made it to the Open’s fourth round and that’s not including Naomi Osaka, who is from Japan but moved to Long Island at age 3.

Martin Black, the USTA’s director of player development, was not immediately available for comment Monday on the disparity.

Black talked to The Post on Saturday regarding Coco Gauff’s emergence, and is excited.

“It’s her poise — handling moment after moment against really good players,’’ Blackman said. “It’s problem-solving, dealing with everything that comes along with 15-year-olds. That was really impressive to me. She held her own [against Osaka]. But she’s just starting her career against someone who has won two Grand Slams. It’s just the beginning.”

The beginning for the men is still unclear.

Zverev’s first venture into the second week of the U.S. Open is over, losing to No. 20 seed Schwartzman under the Arthur Ashe Stadium roof.

Five of the top eight seeds are out of the men’s event before the quarterfinals. Schwartzman is in the quarterfinals here for the second time in three years with a 3-6, 6-2, 6-4, 6-3 win. Zverev has been something of a double-fault machine and banged 17 in the loss. … Rain caused postponement for matches on the side courts Monday until 5 p.m.

Matteo Berrettini became the first Italian man to reach the U.S. Open quarterfinals since 1977 by knocking off Andrey Rublev, 6-1, 6-4, 7-6 (6). The 23-year-old, 24-seed will appear in his first-ever grand slam quarterfinal against 13th-seeded Gael Monfils, who defeated Pablo Andujar, 6-1, 6-2, 6-2. It is the Frenchman’s ninth career grand slam quarterfinal, but first since 2016, when he reached the Open semifinals.