Barcelona coach Ernesto Valverde said on Monday he expects a Roma backlash in their Champions League quarter-final second leg at the Stadio Olimpico on Tuesday.
The Spanish league leaders have one foot in the semi-finals after romping to a 4-1 first leg victory in the Camp Nou last week as Roma proved partly the architects of their own downfall in scoring two own goals.
But Valverde isn't counting his chickens against a side that hasn't reached the semi-finals since 1984.
"I've been doing this long enough to know that extraordinary things can happen in a game," said Valverde at Monday's pre-match press conference in Rome.
"It'll be the same kind of game as the first leg, but they'll have even more intensity.
"History says that, at our level, it's hard to score against us, but we can't think that they don't have a chance or they won't try.
"A mistake, an excess of confidence, they could cost us dearly and we are at the doors of the semi-finals."
He added: "We can't think we've already won, it's all to be decided. We got a good result at Camp Nou, we have the advantage, but we need to play as though it were 0-0."
Roma managed to stifle Barca star Lionel Messi in the first leg, which was a source of pride for their coach Eusebio Di Francesco.
"Everyone was saying he wasn't fit and suddenly he scored a hat-trick (in La Liga) on Sunday," said Di Francesco.
"This means we managed to limit his movement between the lines. We have to reduce the space around him as much as possible, wherever he pops up on the pitch."
Di Francesco has been boosted by the return of Belgian midfielder Radja Nainggolan, who missed the first leg due to a muscular problem, and Turkish winger Cengiz Ünder, who was not in Barcelona either.
"I'm someone who always wants to play, even in pain," said Nainggolan. "I decided to leave room for others, who were in a better condition than me, but now I'm better again."
Barca midfielder Sergio Busquets is a doubt as he recovers from a fractured toe, but Valverde can count on the attacking duo of Messi and Luis Suarez.
"Every team and coach wants to stop the best players from hurting them. We have Messi, and that has an effect on the opposition," said the Barcelona coach.
"They did well in the first leg, but we know he can always find the key to be decisive. Then of course we'll have to be wary of (Edin) Dzeko and others."
Barcelona last reached the semi-finals in 2015 when they won the title.