It's true ... the former World Series champ sang his face off all season on "The Masked Singer" -- with his voice even making Nicole Sherzinger cry before he was eliminated from the show Wednesday!!

The 42-year-old sang a rendition of Tim McGraw's "Humble And Kind" under the guise of The Rhino ... and it was so good, the Pussycat Dolls star was moved to tears.

Check out the footage ... Zito's twangy sound really had Nicole wiping away the waterworks!!

But, as it turns out, even that wasn't enough to save the former Cy Young winner from elimination ... he was booted from the show just short of making next week's finale.

Of course, it was a valiant effort from the ex-San Francisco Giant ... he finished in fourth place, and the judges praised him for being super authentic throughout the competition!!

BTW, Zito's been doing the music thing for a while -- and told us back in 2017 why he hopes to add a Grammy to his trophy case one day.

Also, don't feel too bad for Barry about the exit -- it's pretty much the only L Zito is taking in 2020 ... he just had a new baby, and his family is cute as hell!!