Carlo Ancelotti has said Paris Saint-Germain can look forward to "a fantastic future", whether or not they knock Barcelona out of the Champions League quarter-finals at the Camp Nou.
He predicted great things ahead for the big-spending, Qatari-backed Paris club and said Wednesday's result would have no impact on their growth into a major power in European football.
"It could be just a very good step to improve, but it changes nothing in the future of PSG," he said.
"PSG are trying to build a fantastic future, and it'll be fantastic if we win or don't win. If we don't win, we'll try to reach the semi-finals next year.
"I'm not worried. Everyone from PSG is happy to be here. It'll be a great evening. Everyone knows it'll be difficult. We only have a slim chance, but we have a chance. We showed in the first leg we can do it against a fantastic team.
"We have to use all our qualities, defend well and attack well, be patient, be solid. All the qualities you can give, you have to give tomorrow."
Argentina international Messi was involved in part in some of Barcelona's training session on Tuesday, but Ancelotti said: "It [whether or not he plays] doesn't change our strategy. It'll be the same. We need to be confident and show personality in a very difficult stadium against probably the best team in the world."
The Italian confirmed that Alex was fit to play, but said his other Brazilian central defender, captain Thiago Silva, faced "a very important training session" 24 hours before the game.
He also suggested that former Barcelona midfielder Thiago Motta was still short of fitness, raising the prospect that 37-year-old David Beckham - whose first-leg display was praised by Ancelotti - will start again.