If you're a baseball fan with a quarter of a million dollars lyin' around -- you're in luck ... 'cause an ultra-rare bat that Hall of Famer Roberto Clemente once used and signed is about to go on sale!!
TMZ Sports has learned ... the Hillerich & Bradsby signature model U1 bat that Clemente swung during the 1971 season is hitting Heritage Auctions in February -- and it's awesome.
The 36-inch, 35.5-ounce relic has been photo-matched ... and it's also been autographed by Clemente himself.
The inscription -- which Clemente made out to famed memorabilia collector Carey Diab -- reads, "To my friend Carey, Best Wishes Always, Roberto Clemente.