DALLAS — The Yankees’ signing bonus offer to Juan Soto was $60 million, a source told The Post. 

It was part of their 16-year, $760 million bid to Soto that fell short to the Mets, who won the lefty slugger at 15 years, $765 million, which included a $75 million signing bonus. 

The Yankees were at $712 million on a 15-year offer Saturday. At the time, the Red Sox were thought in the same general area, but their officials began to doubt their ability to land Soto. 

The Blue Jays were believed to be higher than that, but it was always viewed as a long shot that Soto would go to Toronto. 

The Yankees, for luxury-tax purposes, were hoping to keep Soto in the $47.5 million annual range, so when Scott Boras asked if they could go a little further, the Yankees decided to add an extra year in their bid — a 16th year to get to a total of $760 million. 

Steve Cohen and the Mets ultimately outdid the signing bonus, the total offered and the average annual value with their 15 years at $765 million — a $51 million annual average. 

The Yanks were asked once again to counter but did not, a source said. That left the Mets as the winner for Soto.