Imagine a hypothetical CL semi-final game between two sides comprised of these players:
La Liga Star XI: Casillas, Alves, Puyol, Ramos, Carlos, Zidane, Iniesta, Xavi, Ronaldo, Suarez and Messi.
Bench: Koeman, Marcelo, Modric, Kroos, Busquets, Neymar, Bale, Benzema, R9.
VS
Premier League Star XI: Cech, Walker, Terry, Ferdinand, Cole, Gerrard, Lampard, De Bruyne, Henry, Shearer, Salah.
Bench: Schmeichel, Van Dijk, Vidic, Neville, Scholes, Viera, Rooney, Hazard, Van Persie.
Imagine first leg being at Anfield and the second leg at Santiago Bernabeu. What would be the aggregate scoreline?
For LaLiga team , xavi out Busquets/casemiro in
For Prem , Lampard out , Viera/Roy Keane in
Xavi and Busquets are non-negotiable. You can then decide between Zidane and Iniesta.