Dennis Bingham

We all know that an umpire does not drawn attention to an improper batter batting out of order. That is the responsibility of the opposing team to make an appeal. However, what if an umpire discovers an ineligible (illegal) player playing defense or running out to pinch-run? By ineligible, it is meant that the player should not even be in the game (removed from game earlier, ejected, etc.) Does the umpire immediately remove the illegal player immediately upon discovery or does he wait until the opposing team appeals the use of the player?