Ivan Rakitic said Edin Dzeko is “one of the best strikers in the world” and Barcelona must be wary of “strengthened” Roma.
They meet at the Stadio Olimpico in the Champions League on Wednesday, kicking off at 19.45 UK time (18.45 GMT).
“Roma are a very well-known club and they've really strengthened. It's the first match of the group stage, so it's very important,” the Croatia international told Barça TV.
“We'll play in a full stadium and the fans will get behind their team. It'll be a great game of football and we'll do our best. Our footballing philosophy doesn't change and we hope to win the match.
“They're a very organized side. Like many Italian teams, they know what to do at every stage of the game. They've really strengthened up front with Dzeko, one of the best strikers in the world. We have to be ready in every area of the pitch because they're a top side and we can't give anything away.
“We have the utmost respect for our opponents. Roma have strengthened a great deal and I've got friends who play for them. It will be a very tough group. We'll give it everything and we want to make progress in the competition.
“I've always liked it. I've always followed Serie A because geographically it's not far from Switzerland and Croatia. It's a very strong league which has gone through a tough period, but we've seen the results of the efforts clubs have made this summer.
“A number of my team-mates in the national team now play their football there. I keep an eye on how they're doing and wish them all the best, except when they play us of course.”
Barcelona beat Juventus in the Champions League Final last season, so Rakitic is targeting an historic double.
“We have the ambition and desire to make more history. No one has ever won this competition two years in a row and we'd love to be the first to do so.
“But let's take things one step at a time. Let's perform well in our first match and get through the group. We'll try to go far in the competition, one step at a time, and raise our game when we need to.”