David Wells to Luis Severino, 'S**t Happens'

We spotted NY Yankees legend David Wells out in NYC -- and asked if he had any advice for Luis Severino, the Yankees ace who's been struggling recently.

Wells told us he doesn't watch much baseball these days ... but did drop a few pearls of wisdom for the 24-year-old fireballer.

"S**t happens when you struggle ... find a way out of it!"

The clip is pretty great ... Wells talks locker room stories, golf and even gives props to our photog for dodging obstacles in the street.