Tbf, i think that this proposed starting XI could have easily made it vs Derby. No risk whatsoever to play RLC in place of Mikel and Boga in place of Schurrle imo. Once you get that out of the question, it's a matter of what are players like Schurrle, Mikel, Salah (the list goes on) to us as you say. Squad players are there to provide alternatives. Days will eventually come in important competitions (PL, CL), when starters will be injured or suspended or out of form or not in the manager's tactical plans. Jose won't play the likes of Boga and RLC in those situations of course. I hope you get my point. Matches like Sporting (we were top of the group no matter the result ffs) or Derby are ideal for youth integration. No one said anything about PL or CL fixures where things are really very very serious and important.