Keith Hernandez is in midseason form already.

As Gary Cohen began SNY’s broadcast of the Mets Grapefruit League opener against the Cardinals in Port St. Lucie, Florida, he introduced broadcast partner Ron Darling and then noted with a laugh that, “Yeah, Keith already has a day off. More on that later.”

Hernandez has been known to keep a more relaxed schedule than Cohen and Hernandez’s former teammate, Darling.

This time, though, as Cohen noted during Saturday’s game, Hernandez had “ a good excuse.”

As described by Cohen and Darling, Hernandez was in his hometown of Pacifica, California, where both Hernandez and his brother, Gary, were being inducted into the Pacifica Sports Hall of Fame.

While Keith had a 17-year Major League career, including seven with the Mets, Gary played college and minor league ball.

Cohen called Gary Hernandez “a tremendous star at the University of California who made it to Double-A in the minors.”

Gary Hernandez, 72, was drafted in the 17th round by the Cardinals in 1972 out of Cal and played four seasons in the majors.  

Younger brother Keith, 70, was selected by St. Louis in the 42nd round of the 1971 draft out of Capuchino High School in San Bruno, California.

Hernandez now is in the second year of his most recent contract with SNY, a three-year deal signed prior to last season.

The ex-Mets first baseman, who had his No. 17 retired in 2022, was slated to work around 110 regular-season games each of three years in his current contract, The Post’s Mike Puma reported when the deal was complete.

Saturday’s game also represented the debut of new Mets manager Carlos Mendoza, who replaced Buck Showalter in the dugout.