Toss from dugout to first baseman?

The ball that they play with can get scratches and scuffs on it, so they don't want to use it.

When they are on the way back to the dugout, they toss them another ball so they can use it to warm up the infield on the next inning. They throw them the ball so they won't forget to take it out at the start of the next inning.

Next time you watch a game, before the inning starts, you'll see the first baseman throwing the ball to the other infielders.

Way to be observant during the game.

The toss coming from the dugout is a coach or another player giving him a ball to use during warmups the next inning. The ball that he rolls into the dugout could be a couple of different things.

1) Ball goes to a fan sitting by the dugout

2) Ball goes to the ball boy who recycles it into play

As you probably know, the Major Leagues go through balls in bunches. Umpires throw a ball out when a pitcher throws one in the dirt or it is fouled off at the plate.

The reason someone tosses him the ball at the end of the inning is so he has the ball in his glove at the start of the next inning when he takes the field. He uses the ball to throw to the other infielders to keep their arms loose and warm. The give him the ball when he comes to the dugout so he doesnt forget when his team is at bat.

That ball is used for the next inning.

It's a practice ball. The 1B throws it around the infield as a grounder...and they fire it back to him.

It's warm up throws for the infield in between the pitcher's warmup tosses.