Confidence key for Keita as Roma await Zidane's Real

"How we line up against them is down to the coach, but for me, we have to believe in ourselves and go on the pitch convinced," said the Malian ahead of Wednesday's tie in Rome's Stadio Olimpico.

Former Barcelona midfielder Keita knows his opponents well having won 11 matches with the Catalans in the 17 times he played against the arch Liga rivals.

"This game will be difficult, but not impossible," added Keita of Real's miserable record against Italian teams in the competition.

Roma coach Luciano Spalletti, brought back to the club recently following the sacking of Frenchman Rudi Garcia, was at the helm when the Italians prevailed over two legs in 2008.

Roma beat Real 2-1 at home, a score they would repeat at the Santiago Bernabeu before being humbled 3-0 by eventual winners Manchester United in the quarter-finals.

Real have made it to the semi-finals of the competition the past five seasons, claiming their historic 10th title, 'La Decima', in 2014 when current manager Zidane was assistant to Carlo Ancelotti.

Efforts to go one step further last year were rebuffed when Juventus claimed a 2-1 win in Turin and booked their final place against Barcelona thanks to a 1-1 draw at the Bernabeu.

But there is little chance Zidane is entertaining another early exit and the former France and Juventus great comes to Rome with only one defeat from his six-game tenure so far, during which Real have scored 23 goals.

Despite it being his Champions League debut as coach, Zidane's past experience in the competition gives him the knowledge of what it takes to succeed in Europe's premier club competition.

"When you're a player, you dream of playing in the World Cup, but you can dream of the Champions League every year," said Zidane.

"We are prepared and we want to do something important in this competition."

Although Welsh winger Gareth Bale remains sidelined with a calf strain, Real welcomed left-back Marcelo, who missed a 4-2 win over Athletic Bilbao at the weekend due to a a dislocated shoulder, back to their matchday squad.

With central defender Pepe sidelined, Raphael Varane will keep his place alongside Sergio Ramos despite being sent off in a poor display at the weekend when Cristiano Ronaldo hit a brace and James Rodriguez and Toni Kroos added their names to the scoresheet.

Karim Benzema, who set up Ronaldo for his first on Saturday, admits it won't be all plain sailing. "The key to the tie is us. If we are on top form we will win," said the French striker.

"We have to take into account the speed of their forwards, but we are Real Madrid, for me the best team in the world, and we have the best defenders in the world."

Roma, it seems, have been warned. Despite Keita's call for confidence, fans will be hoping Roma at least produce the kind of display that held Barcelona to a 1-1 draw in the group stages earlier this season, and not one that led to a 7-1 humiliation at the hands of Bayern Munich in Rome last year.

On the plus side, Roma claimed a fourth consecutive league win last weekend for the first time since October.

Argentinian midfielder Diego Perotti admits, Bayern, Barcelona and Real are "all favourites for the title".

But it seems Keita's words are already rubbing off: "They're not going to find it easy against us. We'll be giving it our all, and we have possibilities to cause an upset in this tie."