Roma manager Rudi Garcia insists his team must not view Barcelona as "invincible" when the Serie club takes on the UEFA Champions League holder at Camp Nou on Wednesday (AEDT).

Garcia's men have the benefit of having claimed a 1-1 home draw with Barca in their Group E opener, but Luis Enrique's team have kicked on to find imperious form since then.

Barca was close to its irresistible best in dismantling bitter rival Real Madrid 4-0 on Sunday (AEDT) and could hand a first start to Lionel Messi since September, with the Argentina superstar fit again after knee ligament damage.

Defeat may take Roma's qualification fate out of its own hands, as it sits second in the standings - one and two points clear of Bayer Leverkusen and BATE respectively.

"Football is a beautiful game and it is not always the best team who wins and I don't believe any team is invincible," said Garcia. "If we don't believe we are worthy of playing here, we are going to lose. We have to take our chances and work hard.

"We know Barcelona will have the ball most of the time, but we have to make the best of the opportunities we get. We cannot defend throughout the entire game, because we will lose. 

"We also have a good team with good players and we believe we can get a result.

"The match against Barcelona is important, but not decisive. We have our destiny in our own hands and we are here to win, even though not many teams succeed here.

"Barcelona are one of the best teams in the world and a victory would change our future."