We know what you're thinking ... the Expos were a baseball team, and well, Brady's a football player, right?

Not always!

Way back in 1995, Tom was a talented high school baseball player -- a power-hitting lefty catcher -- who was so damn good, the Montreal Expos selected him in the 18th round of the MLB draft.

Of course, TB12 opted to go to college, instead, the University of Michigan, and was ultimately picked in the 6th round of the 2000 NFL Draft.

But, this week (on 12/12, a nod to Tom's jersey number), Fanatics and Brady, along with Topps, reimagined what things might've been like if TB had stuck with baseball.

The card giant released several rare Brady/Expos cards, including the totally unique, one-of-one Superfractor.

That card was pulled Tuesday night by the collectors at Triple Diamond Sports Breaks ... and experts have said it could be worth over 6 figures!

If you were hoping to pull that card, you're out of luck ... but, there's still another card out there that's not only been signed by Brady, but also inscribed with "If baseball doesn't work out, there's always football."

In fact, there's a collector who wants that card so bad that they've placed a $500k bounty on it!

Topps also had a little fun at Tom's expense ... with some help from New York Giants Super Bowl hero David Tyree.

But, cool cards weren't the only part of the reimagining ... the National Baseball Hall of Fame Museum created and shared a Brady HOF plaque (does anyone doubt he would've found a way to be one of the greats?!)

Major League Baseball, with help from Pedro Martinez, Vlad Guerrero Sr. and Larry Walker, also created a commercial about Brady the baseball player, fit for the alternative universe.