contract question

Hey, is anyone here savvy to what the deal is with new players being called
up during the season?

Say Voros for instance, can he play only so many games before they actually
have to send him back or write up a new deal? Or, does his kind of contract
allow us to keep him for as long as he fights for position?

I know with some call ups, it seems they only stay 9-10 games at most. I
wasn't sure on the policies and with a healthier lineup leave only a few
extra spots. We are going to have too many players soon. Does that mean we
will have to risk someone else on waivers to keep him here?

Thanks.