Does the player have to come out?
 

2 man player catches the ball unguarded in my corner as I am the lead. Kid beg jumping on one foot over and over. I call travel on him. His teammate comes over and says "it's his knee." He picks him up and carries him the 8 ft or so to the bleachers. He sits him in the bleachers with his leg up on the bleacher as well. They start shoving on his knee repeatedly. His teammate tells me "it pops out of place." After about 30 seconds He says there is it and jumps up without even limp. Meanwhile there is a sub at the table for him that comes in.

My question is what if there was no sub? The coach never came out. I assume bc he knew what was going on. Would the player need to be removed as we stopped play for approximately 1.5 minutes.

Remove player. Besides everything surrounding the actions of the injured player and teammate, ninety seconds is too long.

Why wouldn't you call the coach out long before 90 seconds passed?

What triggers the sub requirement: the coach actually coming out, or the coach being beckoned onto the court?

Beckoning. And if the coach comes on to the court he/she is considered beckoned (at least in my games).

I was the lead as far away from the Coach's bench. I was looking at the kid in the bleacher going Mel Gibson from Lethal Weapon on his knee. It was probably my shock that keep me from calling him out. When I turned to look at the Coach he has a sub already coming in. Perhaps my partner had beckoned the Coach. I'm honestly not sure.

I'd ask for a sub or for the coach to call a timeout.

We're not waiting.

Case 3.3.6B " A1 may remain in the game if ... A1 is ready to play immediately. There is no set amount of time as to what is "immediately," but it should not involve more than a few seconds..."

There's what I was thinking of. I thought he would have to come out since the delay was so long but couldn't find the ruling I need.