The phrase "to make the squad" means to be chosen or selected as a member of a sports team or a group of individuals with a common goal. Full definition
But it seems like he was understanding about not making the squad. (sbnation.com)
If we buy really buy 2 more players in mid and wing / striker few top class players will not even make the squad let alone making the bench! (justarsenal.com)
Once we have that, we improve on each position to make the squad stronger. (justarsenal.com)