Sergio Martínez, slow burn

The 19-year-old midfielder impressed in Castilla's 2-2 draw with Hércules after returning to the starting XI, scoring 8.1 on Sofascore with 92% pass accuracy.

Sergio Martínez, signed by Racing Santander for €3m over the summer from Racing Santander, is progressing through a carefully managed development plan at Castilla under coach Julián López de Lerma. The 19-year-old from Cantabria had attracted interest from Leipzig, Brugge, Chelsea, Barcelona and Atlético before Madrid secured his signature, with manager Mourinho personally conveying confidence in his potential.

After an initial adaptation period that saw him alternate between starts and the bench in October, Martínez returned to Castilla's starting XI against Hércules and delivered an impressive performance in the 2-2 draw. He created two clear-cut chances that went begging when Hércules defenders cleared off the line, while also controlling the midfield with personality and confidence.

Statistically, he recorded 92% pass accuracy (58 of 63), completed all four long passes attempted, generated three chances and won six of ten duels.

The club's approach remains patient and methodical. Internally, there is full confidence in the midfielder's trajectory, with officials emphasizing this is a signing for the long term rather than immediate impact. Mourinho has monitored his progress closely, including watching him in the U-20 Intercontinental Cup and training sessions with the first team.