Before he was a Mets rotation anchor, David Peterson was a son of the stables

The Mets will be in St. Louis on May 3, but David Peterson likely will be keeping an eye on what’s going on at Churchill Downs that evening.

Though the left-hander is off to another solid start in the Mets’ rotation — he enters Friday night’s scheduled start with a 2.70 ERA and more than a strikeout per inning — baseball wasn’t first on his list when it came to being a professional athlete.

Instead, it was a vastly different sport that interested him.

“The first thing I ever wanted to be was a jockey,’’ the 29-year-old said recently.