Boxer Jarrell 'Big Baby' Miller Says Failed Drug Test Cost Him $30 Mil

Heavyweight boxer Jarrell "Big Baby" Miller says the failed drug test that forced him out of his fight against Anthony Joshua cost him around $30 MILLION!!!!

... and yeah, he still thinks about it all the time!!

Remember, Miller was the guy ORIGINALLY slated to fight AJ on June 1 at Madison Square Garden -- but when "Big Baby" failed the test, Joshua's people signed Andy Ruiz as a last-minute replacement.

And, we all know what happened next -- Ruiz beat the dog snot out of Joshua ... and now Andy is trying to lock up a $50 million rematch deal.

So, when "Big Baby" joined the guys on the "TMZ Sports" TV show (airs weekdays on FS1) -- we asked if he ever thinks to himself, "That shoulda been me!"

"It was gonna be a massacre," Miller says ... "But, sometimes God has plans for you."

Miller ain't mad at Ruiz -- in fact, it's the opposite -- the two have been good friends for years and Miller says he couldn't be happier for the boxer.

But, when we asked how much cash he thinks the drug test ultimately cost him, Miller dropped some REALLY BIG numbers ... and explained, "You know how many cheeseburgers that is just now!?!!

Don't worry, Miller says he's getting his career back on track and plans on fighting later this year as soon as his suspension is up.