The Warm-up: Roma ready themselves for ultimate European test

With Wednesday's first leg taking place at the Camp Nou, can the Giallorossi find a way to stop the great Lionel Messi and ensure they bring the tie back to the Stadio Olimpico with everything still to play for?

The pre-match reading

• Eusebio Di Francesco's pre-match press conference
• Fazio focused on things Roma can control
• S quad list: Perotti and Gonalons miss out
• Opinion: Why match dynamics could yet help Roma
• Gallery: Training at the Camp Nou
• Quiz: Roma's Champions League campaign so far

The story so far...

Roma have reached the last-eight for the fourth time in their history: after winning a group that included Chelsea, Atletico Madrid and Qarabag. The Giallorossi beat Chelsea 3-0 at home to help propel them into the knockout stages, clinching matters with a 1-0 win over Qarabag on the final matchday.

In the last-16, Eusebio Di Francesco's side progressed on away goals - beating Shakhtar Donetsk 1-0 at the Olimpico after losing 2-1 in Ukraine.

Barcelona, meanwhile, are in this stage of the competition for the 11th season in a row. They also emerged as group winners, breezing clear of Juventus in a group that also contained Sporting Lisbon and Olympiakos.

In the last-16 they saw off Chelsea: drawing 1-1 at Stamford Bridge before romping to a 3-0 win at the Camp Nou.

The form guide

Roma come into this game unbeaten in their last five - although their last outing saw them held to a 1-1 draw with Bologna at the Stadio Renato Dall'Ara. They currently sit third in the Serie A standings.

Barcelona, meanwhile, also drew their last game - coming back from 2-0 down to grab a point against Sevilla as they continued their march towards the Spanish league title.

Barcelona's form is impressive: they are unbeaten in nine Champions League games, have kept a clean sheet in the last seven of those, and have not lost a game at home all season.

Team news

Coach Eusebio Di Francesco's biggest decision surrounds Radja Nainggolan - with the boss revealing the all-action Belgian midfielder had just a 50% chance of playing during his pre-match press conference.

Winger Cengiz Under has already been ruled out of the contest, along with long-term absentee Rick Karsdorp, but Lorenzo Pellegrini is available after overcoming a knock suffered on international duty.

Barcelona will be able to welcome Lionel Messi and Sergio Busquets back to full availability, but former Roma defender Lucas Digne is unavailable.

January signing Philippe Coutinho is ineligible for this phase of the competition, having represented Liverpool in the group stages.

The view from both sides

Eusebio Di Francesco: "Before this game, more than any other, I have looked to keep everyone on their toes: no-one is guaranteed to play, anyone can make the difference for us.

"Tomorrow it doesn’t matter who’s on the pitch, in whatever position; tomorrow it will be Roma on that pitch, not individuals. That’s the message I’ve given to the lads: we must play as a team, now more than ever.”

Ernesto Valverde: “I doubt very much that the tie will be won in the first leg," he told the assembled press on Tuesday. Given the level of our opponents, it would be useful not to concede and still win, but we are aware that playing a good match won't be enough.

"Watching their group games, it wasn't a surprise that Roma were top, nor is it a surprise that they are in the quarter-finals. They play to attack and defend with solidarity. We will have difficulty progressing. It is an attractive knockout tie.

"We face it with enthusiasm and a 50 percent chance of winning, just like them."

Opposition danger man

LIONEL MESSI

What more can be said about Messi, that has not already been said a thousand times before? Barcelona are blessed with some of the best players in the world but it is Messi who they all turn to, the magician who makes everything click into an even higher gear. And that will be the case again on Wednesday.

Suffering from an injury recently, the Argentine showed no signs of being unduly affected as he came off the bench at the weekend to salvage a draw against Sevilla with a virtuoso individual cameo.

Clearly, if Roma are to have a chance in the tie, they will have to limit Messi's effectiveness as much as possible. Many have tried and failed in that particular task over the years: but it remains inarguably the crucial way to disrupt Barcelona's attacking threat.

Roma's one to watch

KOSTAS MANOLAS

It seems highly likely that Roma's challenge will be built from the back on Wednesday night and, in that regard, the partnership between Kostas Manolas and Federico Fazio (or, possibly, Juan Jesus) will be absolutely vital.

Manolas has had a habit of raising his game for the biggest games against the biggest opponents, and games don't get much bigger in both categories than this one.

With speed, physicality and aggression, Manolas has the raw skills to make life very difficult for Luis Suarez and the rest of the Barcelona front line.

With Alisson Becker behind him the Greece international has something of a safety net but, if he can help marshal the Roma backline with a minimum of errors, it could prove a solid foundation on which the Giallorossi can build upon.

Possible line-ups

Di Francesco has already said he will leave it late to decide whether Radja Nainggolan is fit to start, a late decision that could have further ramifications for his starting XI. Lorenzo Pellegrini could be in line to come into the side if the Belgium is considered not ready.

Elsewhere, his main decisions will involve who starts in attack - with Gerson, Diego Perotti and Stephan El Shaarawy likely fighting for the two spots alongside Edin Dzeko.

With Lionel Messi and Sergio Busquets both passed fit, the issue for Ernesto Valverde is how best to arrange his attacking options. Without Philippe Coutinho it seems likely Messi will partner Suarez in attack, with Ousmane Dembele offering additional attacking support from the right.

In central midfield, Busquets' return could see Paulinho moved to the bench - with Andres Iniesta and Ivan Rakitic both starting.