The answer to this is No. Before the start of each game, both teams are required to provide a list of players to the umpire, the scorers, and the opposing team. This will allow the people to know who is actually playing. If the umpire decides to change the players, then the opposing captain has no right to question this according to the rules especially since it is done lawfully.
There should also be no objection to where the substitute will be placed. There is just one thing that the substitute cannot do and that is to play as a wicket-keeper. There are still other rules about nominations and substitutes that you should know more about if you are planning to watch or even play cricket.