Marcelo injury blow: who can plug the gap?

The treatment room at Real Madrid's Valdebebas training base has already been overbooked this season and one more important name has been added to the list of inpatients.

With coach Rafa Benitez looking forward to having a near-enough full compliment of players at his disposal this week after injuries caused havoc to his early-season plans, Marcelo's premature departure from Tuesday night's victory over Paris Saint-Germain will add further work from the club's under-fire medical staff.

The Brazilian failed to even finish the first-half at the Santiago Bernabeu, hobbling off after half-an-hour before taking his place on the bench with a large bag of ice. His initial absence was not felt with Nacho, his replacement, scoring the winner against the French side just two minutes after his introduction. Madrid kept another clean sheet, in-turn ensuring they remain the only side not to concede a goal in this season's competition, and sat top of Group A and La Liga after the match.

The full details of Marcelo's injury have yet to be disclosed but the flying full-back is set to be absent for Sunday night's big match at Sevilla and his presence on international duty with Brazil is also in doubt. Madridistas will be keeping everything crossed that one of this season's star performers is back in time for the crucial El Clasico clash against Barcelona on Saturday, November 21.

The 27-year-old has been superb for Madrid so far this season, perhaps being the team's play-of-the-season to date alongside Keylor Navas. He is one of just two players to have started all ten league matches, the other being Cristiano Ronaldo, and has missed only one match in the Champions League, the 2-0 away win at Malmo just days before the big derby match at Atletico Madrid.

His absence will undoubtedly be felt in the coming matches, however many he is likely to miss, and not only in a defensive nature but also in attack. He may be part of the tightest defence in La Liga, and the only defence yet to concede in the Champions League, but he has also scored twice and provided one assists, as well as causing havoc in hogging the left touchline.

Benitez will now have to search for the best solution and after letting Fabio Coentrao leave on-loan in the summer, left-back is perhaps the area of the squad that has least strength-in-depth. Here are the options

- Alvaro Arbeloa

In the only match Marcelo missed this season, away at Malmo in the Champions League, the experienced defender plugged the gap at left-back and although Madrid kept a clean sheet, that came against relatively comfortable opposition and even then the former Spain international struggled to shine.

Arbeloa has the advantage of an experienced head for the big matches - of which the next two undoubtedly are - but people questioned why he was still part of the squad beyond last season, especially with Danilo arriving to compete with Dani Carvajal at right-back.

Those questions were brought to justice in the derby match at the Vicente Calderon when the former Liverpool man, who came on to replace the injured Carvajal, did little to win fans over for the part he played in Luciano Vietto's leveller.

Arbeloa is an option Benitez will consider for the role but he lacks pace, is slow in the turn and playing at left-back, instead of his favoured right-back role, will only magnify those weaknesses - especially against strong opposition.

The 32-year-old may still be able to hack it amongst a star-studded Madrid team in the average La Liga match, but against teams of the quality of Sevilla and Barcelona, teams who attack with pace, he will offer a clear weak link in the Blancos defence.

- Nacho

The youth product picked up plenty of plaudits when he replaced Marcelo against PSG and he is perhaps the favourite to plug the gap while his more experienced teammate is on the sidelines.

There was a hint of fortune about his winner at the Bernabeu, and indeed about Madrid's victory against a PSG side that did everything but find the back of the net, but Nacho committed himself well against one of the strongest attacks in Europe.

He is versatile, having played at right-back, centre-back and left-back, so the role is not a new one for him, and although not blessed with pace, he reads the ball when and alongside more senior players in the back four he is able to provide more than suitable back-up.

One negative point will be the attacking impetus he provides. Few can replicate the threat of Marcelo going forward and although scoring on Tuesday night, that was an exception rather than a role.

The fact Cristiano Ronaldo also plays on the left does not help. The Portuguese star will not track back to help his teammate defensively and that means players such as Toni Kroos, Casemiro and Luka Modric will need to work hard to help their teammate out.

- Raphael Varane

The Frenchman has done enough to warrant a regular starting role alongside captain Sergio Ramos and Madrid are much the better for it.

Varane has been on the verge of replacing Pepe as Ramos' centre-back partner for numerous seasons but Benitez has seen that the time is now right and there is no coincidence that Madrid's defence has been superb so far this term.

The 22-year-old is a viable option at left-back, being left-footed and being blessed with pace, but Benitez will not want to upset the applecart at the back and separate arguably Europe's form centre-back pairing in the big matches.

- Denis Cheryshev

An unexpected name on the list, but an option nonetheless.

When Carlo Ancelotti took over as coach in 2013 the reports were that the Italian wanted to convert Cheryshev into a left-back.

He came through Castilla as a striker and then converted to a winger but Ancelotti and his coaching staff were reported to have seen enough qualities that would enable the player to convert to defence.

That never quite happened and Cheryshev went on to shine playing on the wing for Villarreal. Still, with Benitez showing no faith in playing him in attack, the Madrid-born coach may well see some qualities in the Russian that his predecessor did.

Even if he does, the use of Cheryshev at left-back is likely to be a last-gasp scenario. The fact Benitez has used the 24-year-old just twice so far this season, both times from the bench, coupled with the fact Cheryshev is inexperienced in the role, will leave him as an outside shout.