A potential treble remains on the cards for the Catalan giants, with a place in the Copa del Rey final already secured.
It is, however, Liverpool who provide the next obstacle for them to overcome in continental competition.
The Reds are due at Camp Nou for the first leg of a last-four showdown on Wednesday and Mendieta believes a side chasing down the Premier League crown will provide stiff opposition .
The former Spain international midfielder told Goal of the challenge posed by last season’s beaten finalists and their highly-rated coach: “Barca shouldn’t fear Liverpool, but rather respect them.
“When you get to those stages in the Champions League and looking at how Liverpool has done in the league, it is incredible the work that Klopp has put in.
“I don’t think there’s a favourite, I think it’s 50-50.
“I don’t think there’s any advantage of playing at home, in the way both teams play. I could see it going either way.
“They have different styles and are in great form, which is great for the competition.
“Obviously I hope Barca makes it through and they manage to get another trophy. But we know how difficult and punishing the Champions League can be. So it’ll be about not making mistakes that will be important.”
While saluting the influence of Klopp at Anfield and the threat Liverpool will pose to Barcelona, Mendieta has also hailed the job overseen by Ernesto Valverde at Camp Nou.
A man who now boasts back-to-back La Liga triumphs on a distinguished CV has committed to another year in his current post and will be hoping to enter that agreement on the back of a trophy-laden 2018-19 campaign.
“I think it’s been amazing the way he’s been managing the team both on the pitch as well as in the dressing room,” Mendieta said of a 55-year-old tactician.
“When you coach this team, you need trophies to justify your season.
“Ernesto has already got one now and hopefully there’s more to come in the Spanish Cup or the Champions League.”