The Champions League anthem is ready to sound again for football fans around the world.

It's the most prestigious club competition there is and, for Real Madrid, it is the greatest challenge once again. But it looks like a difficult one.

With a new coach following the controversial sacking of Carlo Ancelotti at the end of last season, the bar has been set very high for Rafa Benitez in 2015-16.

Without many new signings for his playing squad, however, the former Liverpool and Napoli boss may find it tough to compete for Europe's biggest prize.

There is no new striker at the club, even though Javier Hernandez left after his loan spell, while Mateo Kovacic is not the central midfielder many believed necessary and Casemiro returns to replace Sami Khedira in a slightly different role.

The defence is intact and looks strong, but instead of Iker Casillas or David De Gea in goal, Madrid now have the less experienced Keylor Navas and Kiko Casilla - with just two Champions League appearances between them.

Madrid's group is not the easiest, with Shakhtar Donetsk, Malmo and Paris Saint-Germain the rivals following the recent draw and its new format.

The Parisian side is one of the strongest in the competition and especially interesting will be the return of Angel Di Maria to the Santiago Bernabeu and the visit of Cristiano Ronaldo to the Parc des Princes.

Both Madrid and PSG will be expected to progress, but an experienced Shakhtar side could be the surprise and Real face an uncomfortable trip to Ukraine, with the country still in conflict.

The visit to Sweden in November also looks tough, although the opposition shouldn't offer too much resistance to a team like Madrid.

So are Real favourites to top the group? Of course.

Even with James Rodriguez and Danilo likely to miss the first half of the group stages, Madrid will be expected to emerge as victors.

But are they favourites to win the Champions League? That is a much tougher proposition.

Madrid, as usual, will be in the mix for the title, but they are up against a set of rivals that have strengthened well this summer.

Barcelona (with Arda Turan and Aleix Vidal able to feature in the knockout stages), Bayern Munich, Chelsea, Manchester City and Juventus will all be in contention, with PSG perhaps a step back.

Real Madrid's Portuguese forward Cristiano Ronaldo (L) is congratulated by Real Madrid's Welsh forward Gareth Bale. Photo: AFP

Other sides like Manchester United and Arsenal will also be looking to challenge, making it a highly competitive Champions League for Madrid, with Los Blancos beginning a new project while many of the other teams in contention are already established and will be hoping to build on their past work in this competition.

The positives? Madrid's defence looks to be in good hands with Sergio Ramos, Pepe and Raphael Varane all still at the club.

In central midfield, the Toni Kroos-Luka Modric axis is intact as well and should grow in its second season.

And on top of that, the presence of Cristiano Ronaldo. The Portuguese is Madrid's most reliable thermometer: when he is on form, so is the team. And Benitez needs to make sure that is the case.

After that there are many more key players, such as Karim Benzema, Isco, James and Gareth Bale.

All of them are elite footballers and if they can be decisive for Madrid in the biggest matches, the famous trophy could be back at the Bernabeu for an 11th time next May.

Bale in particular is under scrutiny. A hero in his first season as Madrid claimed La Decima, he was disappointing last term and how he fares in the free role under Benitez is likely to have a big bearing this time around.

If he can live up to the hefty price paid to Tottenham in 2013 and match his heroics from Lisbon last year, the Welshman - along with Ronaldo - could be the key to success for Real in the Champions League this season.