Why two different baseballs AA below AAA/Major
 

I have asked this question on another forum with no answer to question -

I am curious why there are different baseballs used for AA and below and AAA/Major Leagues? If the answer is cost - it seems to me Major League baseball would find it cheaper to just buy more baseballs in bulk than to place two different orders for different baseballs?

I gather there is an obvious reason but I don't know it. Thanks.

They were using a pre-tacked ball that was similar to the Japanese league baseball. But I'm not sure they're still doing that.

The reason for the question is I read where the Cubs brought up one of their pitchers to AAA from AA to get him used to the balls used in the Majors. This then begs another question I just thought of, why would a big league pitcher go to AA for a rehab start? Since the balls are different, I wonder what kind of an effect it would have on him. Must quit thinking so much.

Whenever a major league pitcher is rehabbing at any minor league level, they use MLB balls for the game. My buddy just caught a foul ball a couple weeks ago when Kyle Bradish was pitching in Norfolk and he was surprised it was a Manfred ball.

Thanks, interesting. Appreciate that.

My 10 year old caught a ball at a double A game last year and I was surprised it was a MLB ball not rubbed down. Tacky and solid white. Plenty of grip. Was really surprised they used a different ball now.