Zinedine Zidane has made it clear that his system of choice for big matches is 4-4-2.
Eden Hazard will partner Karim Benzema up front on such occasions when he returns from injury.
In midfield, Casemiro, Fede Valverde and Toni Kroos are certain starters, which leaves one spot up for grabs.
That last place in the starting line-up is being contested between Isco and Luka Modric so, who should it be?
The Spaniard returned to the side for Real Madrid‘s home game with Paris Saint-Germain in November and, after impressing on the night, has been a regular starter ever since.
In fact, he’s started in each of Real Madrid‘s big matches since then – El Clasico, the two Supercopa de Espana outings and the Madrid derby.
Isco‘s recent form has been spectacular, showing exactly what he can bring to the table against Osasuna at El Sadar.
With his place in Spain’s Euro 2020 squad at stake, this is a more focused and more determined Isco than we’ve been used to in recent years.
Zidane wants him to be more consistent over the course of the season but knows how important a player Isco is on the big occasions.
The former Malaga midfielder has played 20 games this season, starting 13 of them, but completing 90 minutes just once – he’s often one of Zidane‘s first changes.
He’s also scored two goals so far this campaign, both of them away from home. With him in the team, Los Blancos have won 14 out of 20, giving him a win percentage of 70 percent this season.
The Croatian’s talent is beyond doubt, but he’s not been an undisputed starter so far this season.
He made way in the starting 11 for Isco against PSG and in December’s Clasico at the Camp Nou.
However, his resurgence in recent weeks has caused this major headache for Zidane, who sees the midfielder as a fundamental player for Real Madrid.
In a 4-3-3 formation, Modric would win out over Isco every time but, as an attacking midfielder, Zidane has his concerns.
Modric wins the battle in the goals department, having scored five times this season – his best tally since joining Real Madrid.
In all competitions this season, Modric has made 25 appearances and has been one the end of just one defeat.
With him in the team, Los Blancos have won 15 times, giving him a win percentage of 60 percent.