Sean Casey had a first-hand look at the Yankees’ feeble lineup.

And he knows exactly how to fix it.

Enter Juan Soto.

“They need it, man,” the Yankees’ former hitting coach said during his “The Mayor’s Office” podcast. “The Yankees need a star left-handed bat. For me, a guy like Soto, what is he 24 years old, 25 years old? This would be the guy for me.”

Once one of the most-feared units in the sport, the Yankees lineup fluctuated between unwatchable and meh in 2023.

The team went through two hitting coaches in the fired Dillon Lawson and later in Casey, who passed on returning to the team for 2024 due to family commitments.

The Bronx Bombers ranked near the bottom of major offensive categories in batting average (29th), on-base percentage (.304), slugging (22nd) and OPS (24th).

A lack of left-handed production and power also hurt the Yankees with the team’s lefties producing just a .673 OPS, which ranked 27th in the sport.

The best Yankees’ lineups always featured power lefty bats, but this Yankees team had just the injury-riddled Anthony Rizzo and castoffs like Jake Bauer and Billy McKinney.

This team’s offense needs a gigantic lift and particularly from the left side, and that’s why Soto would be such a great fit for the Yankees — along with 29 other teams.

Soto, who just turned 25, would give the Yankees a dynamic duo alongside Aaron Judge, and provide the left-handed pop that has been missing for years.

There were rumblings the Yankees and Padres had preliminary talks last week, but The Post’s Jon Heyman reported that those have yet to take place.

It’s uncertain whether the Padres would trade Soto with one year left on his contract and if the Yankees could offer the best package, should he be available.

Any team trading for Soto should likely do so with the purpose of extending him, but Hal Steinbrenner has shown a reluctance to pay position players from other teams since acquiring Giancarlo Stanton in 2017.

It’s also possible Steinbrenner might not have the stomach to pony up for another long-term contract, even for a star as prolific as Soto.

Casey believes it’s a no-brainer.

“For the New York Yankees, I look at what they have and you see (Aaron) Judge and (Gerrit) Cole – the window is probably the next six years,” Casey said. “It would make that lineup so much longer if you could get a star left-handed bat. …It would be such a grand slam for them to get a guy like Juan Soto.”