Do they reuse baseballs in MLB?

It seems like a waste to throw those baseballs away, so what happens to those discarded baseballs? In the MLB, discarded baseballs don’t get reused at all. Discarded baseballs go through a process to get authenticated and sold in MLB shops as used memorabilia.

How many baseballs are used in a MLB game?

120 baseballs
It takes about 120 baseballs to play a Major League Baseball game today. 120 baseballs for nine innings of baseball seems a little excessive, yes? Of course you have your classic reasoning for needing so many baseballs. Home runs, foul balls, and your standard throwing a ball to a fan after the last out of an inning.