The Catalans are currently preparing to welcome Los Blancos to Camp Nou for the second leg of their Copa del Rey quarter-final tie on Wednesday night.
However, according to club spokesman Toni Freixa, while Barca are focused on defending their 2-1 advantage from the first leg, they remain upset that Pepe has avoided any retrospective punishment for appearing to intentionally stamp on Messi during the second half of their meeting in the Spanish capital seven days ago.
When asked if the club were actually in direct contact with the RFEF over the matter and trying to push for a ban, Freixa claimed that they were not in a position to do so.
“We are nobody," he told Marca. "Well, actually, we are the victim.
"We understand that these serious incidents took place on a football field and there is a Competition Committee [for that kind of thing].
“We don't want to draw attention away from our objective, which is to get through the tie.
“[But] from the club's point of view, we believe that the Committee has many reasons to act.”
Pepe has been included in coach Jose Mourinho’s squad for the trip to Catalunya, sparking fears of a repeat of the kind of hostility which greeted former Barca favourite Luis Figo when he returned to Camp Nou with Madrid in 2002.
However, Freixa does not ancipate any Barca backlash – on or off the field.
“Our idea is to continue to be an example of sportsmanship and conduct,” he claimed.
“And we hope our socios continue to behave in thay way [on Wednesday].
“We aren't going to suggest to any of our rivals what they should do.
"But what we are convinced about is the impeccable behaviour of our socios, players and coaches and that won't be any different [tonight].”
The clash of the two great rivals kicks off at 22.00CET, with full coverage on Goal.com.
Starting in November and continuing through to the middle of February, Goal.com is publishing exclusive extracts from Graham Hunter's highly-anticipated new book, 'Barca: The Making of the Greatest Team in the World'. Friday's extract looks at how Barca suffered rare disappointment at the hands of Real Madrid in a gripping finale to last season's Copa del Rey. Don't miss it!