There are few more important players at Real Madrid than Casemiro. The Brazilian midfielder may not be the most technical or eye-catching operator for Los Blancos, but the team is rarely as effective when he is missing.

Rafa Benitez was widely criticised for picking the South American in his short spell in charge, but when Zinedine Zidane replaced the Spaniard in January 2016, the midfielder became a fixture in his line-up.

Like many of his team-mates, Casemiro has four Champions League winners’ medals. However, he is the only one to have won the competition in four consecutive seasons as a Real Madrid player, having spent the 2014-15 campaign on loan at Porto.

Carlo Ancelotti’s side reached the semi-finals that year, but missed out on a major trophy at the end of the season after Xabi Alonso left late in the summer and Casemiro departed on loan.

Ancelotti was subsequently sacked and Benitez suffered the same fate after leaving out Casemiro in a Clasico in an attempt to please his president and conceding four goals at home to Barcelona.

Zidane’s Champions League debut as coach came away to Roma and Casemiro did not feature that day at the Stadio Olimpico, but he was back for the return and has stayed there ever since.

On Tuesday, however, he will be missing again in Rome and new coach Santiago Solari faces a dilemma after Madrid lost 3-0 at Eibar with the Brazilian sidelined through injury at the weekend.

Dani Ceballos replaced Casemiro early on against Celta Vigo and shone in the 4-2 win at Balaidos before the international break, but he was badly exposed in the game on Saturday.

The former Betis man is an attacking midfielder who enjoys taking risks, playing defence-splitting passes, providing assists and scoring goals. His conversion into a defensive pivot is far from ideal.

Meanwhile, Toni Kroos has struggled in the position in the past and has admitted he does not enjoy it, while Luka Modric is not at his best in a deeper role either.

Solari has Marcos Llorente, who is the most similar player to Casemiro in Madrid’s squad, but he was left out completely at the weekend and may go out on loan in January. He has been called up for Tuesday's game, though, and could feature.

Young Uruguay midfielder Federico Valverde has good all-round qualities and was on the bench on Saturday, but was not used. He is another alternative, though he lacks experience at this level.

And on Monday, Solari said he could even play a defender in the role when it was put to him that “a lot of water leaks into the ship” when Casemiro is missing.

“There are different players who can operate in that position,” Solari said. “With different characteristics. Every game is also different.

“The centre-backs can play there,” he said. "Ceballos too, who obviously did better against Celta than against Eibar, but the game was different. Llorente is the most similar in the squad. There’s also Kroos, Valverde…”

In Pictures | Eibar vs Real Madrid | 24/11/2018 22 show all In Pictures | Eibar vs Real Madrid | 24/11/2018 1/22 REUTERS 2/22 REUTERS 3/22 REUTERS 4/22 AP 5/22 AFP/Getty Images 6/22 AFP/Getty Images 7/22 AP 8/22 AFP/Getty Images 9/22 REUTERS 10/22 REUTERS 11/22 REUTERS 12/22 AFP/Getty Images 13/22 AFP/Getty Images 14/22 AFP/Getty Images 15/22 AFP/Getty Images 16/22 REUTERS 17/22 REUTERS 18/22 eal Madrid's Luka Modric in action REUTERS 19/22 Real Madrid's Sergio Ramos, Toni Kroos and team mates during the warm up before the match REUTERS 20/22 Real Madrid's Sergio Ramos, Karim Benzema and Raphael Varane during the warm up before the match REUTERS 21/22 Real Madrid's Marcelo during the warm up before the match REUTERS 22/22 General view of action during the match REUTERS 1/22 REUTERS 2/22 REUTERS 3/22 REUTERS 4/22 AP 5/22 AFP/Getty Images 6/22 AFP/Getty Images 7/22 AP 8/22 AFP/Getty Images 9/22 REUTERS 10/22 REUTERS 11/22 REUTERS 12/22 AFP/Getty Images 13/22 AFP/Getty Images 14/22 AFP/Getty Images 15/22 AFP/Getty Images 16/22 REUTERS 17/22 REUTERS 18/22 eal Madrid's Luka Modric in action REUTERS 19/22 Real Madrid's Sergio Ramos, Toni Kroos and team mates during the warm up before the match REUTERS 20/22 Real Madrid's Sergio Ramos, Karim Benzema and Raphael Varane during the warm up before the match REUTERS 21/22 Real Madrid's Marcelo during the warm up before the match REUTERS 22/22 General view of action during the match REUTERS

Without Casemiro, Madrid face a tough test in a game they cannot afford to lose after the Eibar embarrassment on Saturday.

“If one player doesn’t defend, we’re a little worse off,” Solari warned on Monday. “If two don’t defend, we are weaker. If three don’t defend, we can’t beat anybody.”

In the past, the Brazilian has helped to paper over the team’s defensive weaknesses as some of the forward players stay upfield.

“Casemiro has to cover the gaps left by everyone else,” Zidane said earlier this year.

“That, for me, is balance. He has to make sure the match doesn’t go crazy, to calm it down, bring tranquillity, know when is the moment to attack and when to block deep.”

Whoever is included in his place, there is no specialist quite like the Brazilian and in his absence, all of the players will have to work harder. Especially if Solari picks a three-man attack on Tuesday.