A rep for the wrestling legend tells TMZ Sports ... Goldberg was getting work done on his property, when he accidentally knocked his noggin on his tractor -- opening up a big gash near his forehead.

In photos of the injury that the 56-year-old shared on his social media page ... you can see the cut was so bad, it poured blood everywhere.

Fortunately, Goldberg told us it was nothing serious ... explaining it was all "just a flesh wound."

In fact, in true Goldberg fashion, he said he's simply super gluing the thing shut!!!

Of course, bleeding profusely isn't anything new for the WWE Hall of Famer ... he's found himself leaking in the squared circle more often than not over the years.