The first leg at Stamford Bridge was drawn 1-1, meaning Barca have a crucial away goal. It was scored by Lionel Messi, his first in nine appearances against the Blues.
Chelsea must score in tonight’s night’s Champions League last-16 second leg at the Nou Camp to advance.
Willian has scored five goals in five games, including in last month’s first leg against Barca, when he also hit the woodwork twice.
The Brazillian recalled Chelsea’s memorable display in adversity at the Nou Camp in April 2012, when they went on to win the competition.
The Brazilian said of the 2-2 draw: “This game already is in the past. Tomorrow will be a new history, new game”.
“To go through to the next round we have to do a perfect game with the ball and without the ball. That’s the most important thing. To go through to the next round we have to do a perfect game tomorrow.”
Manager Antonio Conte called on Eden Hazard to win “important trophies” to be considered in the same class as Barcelona’s Andres Iniesta.
Iniesta is a doubt with a hamstring injury and Conte waxed lyrical when asked about the differences facing Barcelona without the Spain playmaker.
The Blues head coach was later asked about Hazard, and, though insisting they were different players, occupying different positions, Conte says the Belgium ace must become a more prolific winner of trophies to emulate Iniesta.
“We are talking about two different players with different careers,” Conte said. “Iniesta won a lot in his career and Hazard has to start to win important trophies in his career.
"We are talking about two different players. Hazard is more a number 10 and Iniesta is a thinking midfielder, and a midfielder that thinks, to stay always in the centre of Barcelona’s play.”
Conte insisted he would not be happy if Iniesta is ruled out.
Andres Iniesta is a genius of football. I like to compare him with Andrea Pirlo (who played under Conte for Juventus and Italy). This type of game, it’s right to face the best players. Don’t hope that they could miss [out] through injury.
Hazard, who won the Ligue 1 and Coupe de France double in 2011 with Lille, joined Chelsea after their 2012 Champions League triumph, winning the Europa League the following season.
He has twice won the Premier League, including last season under Conte, and also the League Cup, but has struggled to show his ability at times in the Champions League.
When outlining Hazard’s positional qualities, Conte spoke of the possibility of the 27-year-old playing as a ‘false nine’.
Hazard spoke of his frustrations playing that role in the recent loss at Manchester City, but did well as the focal point of Chelsea’s attack in the first leg, which was drawn 1-1 last month.
Conte could select Hazard in the role again, or use Olivier Giroud or Alvaro Morata as a more conventional striker.
Whoever plays up front, Conte says his players must be prepared to be starved of the ball tonight and make the most of any opportunity.
He said: “The final result for the first leg gives a greater advantage for Barcelona.
We must start the game with great concentration, to stay with our heads on the pitch in every moment, to know there will be moments we have to suffer, to be compact.
"When I speak about ‘suffer’, I think every team must be prepared to suffer possession, because Barcelona like to try to dominate the game and then when you have the ball you must have in your head, your heart, the feeling you have to go to try to take the chance to score.”
The Italian confessed to having sleepless nights ahead of the first leg and called for his players to relish the occasion.
“I think for the manager, for every coach, it’s not simple to sleep a lot, especially before this type of game,” the Italian said.
“In this case, I think I slept the right [amount], but we must be very excited for this type of game. I hope also for my players to have the same excitement.”
Antonio Rudiger is fit to feature after missing last Saturday’s win over Crystal Palace. Chelsea have no fresh injury concerns, Conte said.