During the course of the tournament, you can constantly make changes to your Tournament Mode squad to make sure that you always have a few players in every match.
Any substitutions you make will come into effect in the next match. Effectively, the squad you have at the start of each ICC Cricket World Cup match is the one that will earn points for that match.
Before Match 1, you can make as many changes as you want.
Between Match 1 and Match 21 (Stage 1), you are allowed to make 42 substitutions.
After Stage 1 ends, you can make unlimited subs to your squad.
Between Match 22 and Match 42 (Stage 2), you are allowed to make 42 substitutions.
After Stage 2 ends, you can make unlimited subs to your squad.
Between Quarter Final 1 and Quarter Final 4 (Stage 3), you are allowed to make 18 substitutions.
After Stage 3 ends, you can again make unlimited subs to your squad.
Between Semi Final 1 and the Final (Stage 4), you can make 10 substitutions.