DH Substitution Rules: Can a Player Return?

Question
Hi, my question is if a player is taken out of the game, say left field player substituted for someone else, can they then be brought back later in the game as the dh.

I will use a scenario to ask this question because I think it would help. Say Johnny Damon is switched out in the second inning for a defensive.player who has an arm. Could he brought back into the game in dh position in the seventh inning?
thank you in advance for your help!
-Brian

Answer
Brian,

This isn't allowed for two reasons:
1. Once a player is removed from the game, he cannot return.
2. Players are locked into their spot on the batting order. Therefore, he couldn't be removed from his lineup spot and added to another spot on the lineup.