Lionel Messi Early Autograph Hits Auction Block, Signed As 8-Yr-Old In '95

Lionel Messi's signed thousands of autographs throughout his legendary career ... but how'd you like to own one of his first John Hancock's?! Well, with a fat enough bank account, it can be yours.

Before Messi, now 34 years old, scored a single goal for Barcelona (he's netted 672 goals), he played for a team named called Newell's Old Boys sports club -- a soccer team for 8 to 12 year old boys -- in Argentina.

Goldin Auctions got their hands on an awesome, 20+ year old identification card formerly owned by Messi ... complete with a very child-like signature.

Leo -- who was recently transferred to Paris Saint-Germain -- printed his name LIONEL MESSI.

Beckett -- one of the most respected authenticators in the game -- gave the laminated card their stamp of approval, declaring it "authentic," grading the autograph a gem mint 10 ("pristine") rating.

The 3x Ballon d'Or winner joined the club as an 8-year-old in 1995 ... and they were almost unstoppable. In fact, the squad was nicknamed "The Machine of '87".

Lionel averaged more than a goal a game with Newell.

And Messi isn't the only professional soccer player the club has produced ... Abel Balbo, Jorge Valdano and Gabriel Batistuta, amongst many others, have suited up for the team.

The one-of-a-kind memorabilia hit the auction block late Monday night ... and has a starting bid of $10K.