Player Roles in 4-2-4 Formation

What are the tactical changes associated with substitutions in a 4-2-4 formation? How do substitutions affect player roles in the 4-2-4 system? How do substitutions influence game flow in a 4-2-4 formation? Which substitution strategies are most effective in a 4-2-4 formation?

What are the key responsibilities of centre-backs in a 4-2-4 formation? How do centre-backs mark opponents in a 4-2-4 formation? What tackling techniques should centre-backs master? How can centre-backs improve their ball-playing abilities? What are the advantages of a 4-2-4 formation for centre-backs? What challenges do centre-backs face in a 4-2-4 formation?