Here’s what Getty Images says about this photo:
Catcher Jerry Grote #15 of the New York Mets in action against the Chicago Cubs during a Major League Baseball game circa 1970 at Shea Stadium in the Queens borough of New York City. Grote played for the Mets from 1966-77.
While Grote did in fact play for the Mets from 1966-77, the Cubs wore that style of road uniform only from 1973-77, so that narrows it down a bit.
The Cubs player has a “4” on his jersey. The only Cubs player to wear “4” during that time was Vic Harris — that’s definitely not Harris.