The defender was handed a straight red card after the assistant referee spotted his knee being thrust into Alexis Sanchez's back after 37 minutes
Terry also pointed out that he had not been cautioned throughout the current Champions League campaign and claimed he would not jeopardise Chelsea's chances of progressing to the final by risking a dismissal.
The 31-year-old will subsequently be handed a three-game ban by Uefa and will miss the final if Chelsea progress past Barcelona.
Terry's sending off, which was spotted by the assistant referee, came less than three minutes after Barcelona levelled the tie through Sergio Busquets.
Andres Iniesta soon added a second for Barcelona to send the Champions League holders into a 2-1 aggregate lead, but, just a minute after receiving a yellow card that would rule him out of the final, Chelsea midfielder Ramires chipped Victor Valdes to hand Roberto Di Matteo's side a lifeline.
The game current stands 2-2 on aggregate, with Chelsea leading on away goals, while Lionel Messi missed a penalty in the second half.