The Blaugrana travel to the French capital on Tuesday and have been handed a big boost with the news that their coach will make a long-awaited return to the bench after spending the last 10 weeks undergoing throat cancer treatment in New York.
"Tito Vilanova will be on the bench tomorrow, no doubt: he's the boss, and we're very happy to have him back with us," Roura told reporters at a press conference.
The stand-in boss then warned the Catalans that they will have to be at their very best if they are to emerge victorious against the big-spending Ligue 1 leaders.
"We'll have to be at 100 percent if we want to be able to win," Roura said. "It's very important for us to have reached this stage of the competition, and we're very happy to be here, in Paris. It's a great team with top players, such as (Javier) Pastore, (Ezequiel) Lavezzi and so on."
Roura then acknowledged the versatility of Carlo Ancelotti's team and admitted PSG has more than one gameplan capable of causing his side problems.
"PSG are quick on the break and strong in the air, especially with Zlatan Ibrahimovic and Thiago Silva, but those are only two of their options: they have a lot more tricks up their sleeve," Roura said. "We'll have to adapt a bit, of course, but we won't change the way we play - although we have studied their game carefully."
Roura also revealed that a decision is yet to be made on whether Jordi Alba and Xavi will make their respective returns from injury on Tuesday. Both were included on the traveling squad for the match.
"Jordi Alba and Xavi Hernandez had knocks, but they are coming on well," Roura said. "They were rested last weekend for this, but we'll only make a decision tomorrow, after the final training session."