You know how they say say men with facial hair are "hiding something?"
Well, Eric Karros is one of those guys -- telling TMZ Sports his goatee is masking the scars from a 97-mph fastball that drilled him in the chin back in 2002.
The former L.A. Dodgers 1st baseman says he remembers everything about the pitch that struck him in the jaw -- hurled by former S.F. Giants pitcher Felix Rodriguez.
"Ironically, it was Family Picture Day," Karros says.
Despite the fact it's been 12 years, Eric says he never watched tape of the brutal pitch -- because if he did, Eric says he would have been "too scared to get back in the box."
So, does he still hold a grudge against the man who messed up his face? Check out the clip.