A Barcelona side without Lionel Messi has been found out time and again in recent years. There is little doubt that the Spanish giants are not the same dominating side without their talisman, and come Tuesday night, Celtic will look to exploit that particular aspect when the two sides meet in the Champions League.
"(Messi's absence) is obviously very good news for us," Celtic manager Neil Lennon said. "For me he's the best player in the world. There's sadness too because it's always fantastic to see the greatest here in Glasgow."
Messi has been ruled out for up to three weeks with injury and in the Argentine's absence, a certain Brazilian, who came to Barcelona amid much fanfare in the summer, will be expected to take over the reins.
Neymar has not had a spectacular start to life at Barcelona, but it has been quite good and effective. The talented forward has looked at home in a Barcelona shirt, while his understanding with Messi just keeps getting better with every passing game.
He will of course now be the cynosure in Messi's absence and the Brazilian will do well not to be daunted by the atmosphere at Celtic Park on Tuesday night.
It was the immense support that helped the Scottish champions to one of the upsets of the Champions League last season - a 2-1 win over Barcelona in the group stages.
Repeat that feat, and Lennon will go down in Celtic folklore for leading the Scottish side to two historic modern-day wins.
Celtic also need a win to stay afloat in a difficult group, after suffering a 2-0 defeat at AC Milan on Matchday One. Barcelona, though, will be buzzing after their 4-0 thrashing of Ajax, albeit courtesy a hat-trick from Messi.
"We'll try to limit Barcelona to as few chances as we possibly can and capitalise on the chances we get like we did last year," Lennon said. "For me, Barcelona are a class above Milan -- no disrespect to Milan -- in the way they pass the ball, in the way they create chances, in the pace they have."
Barcelona manager Gerardo Martino played down the need to extract revenge on Celtic, and wants his side to focus on the danger that the Scottish side pose from set-pieces.
"If we keep the ball and focus, we won't concede set pieces where they are very dangerous; they are good in the air and have a great physical presence because they are taller than our players," Martino said.
"I don't particularly believe in revenge in football. Barca players are always expected to do well, they are scrutinised by everybody."
Team News: James Forrest is in line for a return for Celtic, along with Beram Kayal. But Joe Ledley misses out yet again with a groin injury, while Derek Boerigger is a doubt.
Messi, of course, is ruled out for Barcelona, but the biggest crisis for Martino is in defence, with Jordi Alba, Javier Mascherano and Carles Puyol all sidelined. Ibrahim Afellay and Isaac Cuenca are long-term injury victims.
Key Men: Celtic: Giorgos Samaras smashed a hat-trick against Kilmarnock at the weekend and the Greek international will look to impose himself against Barca.
Barcelona: Neymar was rested for the La Liga game against Almeria at the weekend and the Brazilian will be buzzing to make an impact. The quicker he settles into the game, the better for Barcelona.
Where to watch
The match is scheduled for a 12.15 a.m. (IST, Wednesday) start with it set for a live telecast on Ten Sports.
Expected lineups: Celtic: Forster; Matthews, Van Dijk, Ambrose, Izaguirre; Commons, Brown, Mulgrew, Samaras; Stokes, Pukki.
Barcelona: Valdes; Alves, Pique, Bartra, Adriano; Xavi, Busquets, Fabregas; Iniesta, Sanchez, Neymar.