2:02 PM PT -- West just returned to the field ... now umping from third base.
Washington Nationals broadcasters say he required stitches to close the wound.
Scary scene on the diamond Thursday ... MLB ump Joe West took an accidental bat to the side of the head -- and was forced to leave the game after he couldn't stop the bleeding.
It all went down just a few minutes ago in the Nationals vs. Blue Jays game in D.C. ... when Toronto star Bo Bichette swung at a pitch but accidentally let the bat slip from his grasp.
The piece of lumber went backward, connected right to the side of 67-year-old West's head ... and immediately, players signaled for trainers to rush over.
West was bleeding profusely from his ear area ... and despite medical personnel pressing a towel on the wound -- he was forced to go into the locker room for further treatment.
It should be noted ... West didn't seem out of it, and cameras actually caught him smiling -- but there's been no official update from MLB on his status yet.
Originally Published -- 1:47 PM PT