Liverpool made nine changes for the game at St Andrews and Birmingham picked up a crucial point in their battle against relegation that keeps them a solitary point behind Reading and Bolton in 18th place.
Trotters boss Gary Megson recently appealed to Benitez not to compromise the 'integrity' of The Premier League by resting his star names ahead of the two legs of the Champions League semi-final against Chelsea.
Coppell has no qualms about the side sent out by the Spaniard though, claiming the chance of winning a place in Liverpool's European side would have been a huge motivational tool for his Benitez's fringe players.
"You look at the depth they have and sometimes maybe it's of benefit to us because they're bringing fresh people in with a point to prove," said Coppell on the club's official website.
"The players had the prospect of a Champions League final so they won't have been going through the motions.
"I will always say I have faith in the integrity of the league, and that has proved to be the case again."