However, two goals from Craig Bryson and another from Jamie Ward saw the Rams grab a a point which was looking highly unlikely before McClaren's half-time intervention in the home changing room.
"We weren't good enough in the first half and Steve came down at half-time and had a few words to say," Wassall told reporters.
"He made a few changes as well and it did the trick, the second half was much, much better. The response from the players in the second half was absolutely magnificent and that bodes well for the future.
"Steve came back down to the dressing room again at the end of the game and he was absolutely thrilled with the response."
Clough was axed by Derby on Saturday night following their defeat to Nottingham Forest in the East Midlands derby, with the club 14th in the Championship table.