In Lionel Messi, Luis Suarez and Neymar, Arsenal faces the most potent strike force in the game — and a team that will probably be more than halfway to the Champions League quarterfinals after Tuesday's match.
Tactically and physically, Barcelona will ensure the first leg at Emirates Stadium will be one of the toughest matches the hosts have faced in a very long time.
Arsenal's attacking football has taken the team to the last 16 of the Champions League, third place in the Premier League title race and the fifth round of the FA Cup. But it would be a high-risk approach against Barcelona and the likelihood is that Arsene Wenger's priority will be to avoid defeat.
A few things to know about Tuesday's match:
Messi brings not only his exceptional talent but also an impressive track record against Arsenal into Tuesday's game.
Barcelona has beaten Arsenal in their two previous meetings in the knockout stages, with Messi scoring all four goals at the Camp Nou in 2010 as the hosts romped to a 4-1 victory on the night and a 6-3 win on aggregate.
The following season, Messi scored twice in a 3-1 victory that put the home side through 4-3 on aggregate.
Only a torn hamstring kept him out of the 2006 final, when Barcelona came back to beat a 10-man Arsenal side 2-1 in Paris.
It's no secret that Barcelona's attacking trio of Messi, Suarez and Neymar get on very well — on and off the pitch.
"Although they are different characters, on the pitch they are pure harmony," Barcelona midfielder Ivan Rakitic said. "It may sound like an exaggeration, but I say Messi, Suarez and Neymar are the best friends in the world, possibly the best in the history of football."
Arsenal manager Arsene Wenger also highlighted the trio's team spirit.
"They have a great solidarity," he said. "Messi gave the ball to Suarez (from a penalty) because he wanted him to be the best goalscorer . when he (Messi) had the opportunity to score his 300th goal. That means there is something special there."
While the spotlight is bound to fall on Messi, the threat posed by Suarez will not be lost on Arsenal, or the crowd.
His prolific three-year spell with Liverpool nearly won the Premier League for his former club in 2014, when he followed up by scoring both goals as Uruguay beat England 2-1 at the World Cup, effectively ending its hopes of progress from the group stage.
Suarez is in scintillating form this season for Barcelona, both domestically — where he is La Liga's top scorer with 25 goals — and in the Champions League, where he scored five goals in as many games.
Arsenal may well regret, yet again, the club's failed bid for him in the summer of 2013.
Barcelona playmaker Andres Iniesta has been studying his Arsenal opponents and says he knows how challenging they can be.
Iniesta said Arsenal midfielder Mikel Arteta — with whom he grew up at Barcelona's famed La Masia youth academy — is a great player and "in the youth ranks he was a team leader."
Iniesta is also wary of former teammate Alexis Sanchez, whom he described as "very unpredictable" when attacking. "He is physically strong and very capable," Iniesta said.
Arsenal defender Hector Bellerin is another product of the Barcelona youth academy.
Mesut Ozil, Aron Ramsey and Petr Cech will return for Arsenal after being rested for Saturday's goalless FA Cup draw with Hull, while Sanchez and Olivier Giroud are set to start after being on the bench.
Sanchez was lackluster as a substitute but manager Arsene Wenger has no doubts about the Chile international's readiness to face the side he left in 2014 after three years.
"Don't worry about Tuesday," Wenger said. "He'll be tuned in. I think it's more focus. Sanchez, I don't think he was completely ready to come on."
LUIS ENRIQUE'S GOALS
Luis Enrique takes on Arsenal for the first time as Barcelona's coach. However, during the midfielder's playing career, he scored in both matches when the clubs et in the group stage of the Champions Leaue in 1999.
He scored in a 1-1 first-leg draw at the Nou Camp and then again in a 4-2 win at Wembley Stadium, Arsenal's temporary home for Champions League matches.
Harold Heckle in Madrid contributed.