It’s getting harder for Mets to sell their bright future

Mickey Callaway walks to the mound.Jerry Seinfeld was the guest attraction at Citi Field on Friday night complete with Seinfeld Bobblehead dolls and frequent highlights from his long-running sitcom.

You figured it was going to be a good night for the Mets when starting pitcher Jacob deGrom handed Seinfeld the baseball to throw out the first pitch and the comedian went into full wind-up mode and delivered a side-arm strike over the heart of the plate.

DeGrom might have been a bit star struck because his first pitch of the game was promptly deposited in the left-field seats by the Phillies’ Scott Kingery. But after the home run, deGrom settled in and delivered the kind of quality outing the…