Real Madrid midfielder Luka Modric is reportedly set to spend a month on the sidelines after undergoing surgery on his left knee.

Spanish outlet AS (h/t ESPN FC's Dermot Corrigan) reported on Sunday that Modric's blow was likely to see him sidelined, leaving Real Madrid with a dilemma as to who will replace their star playmaker.

Los Blancos manager Zinedine Zidane came to rely heavily on the engine-room tandem of Modric and Toni Kroos en route to last season's UEFA Champions League triumph.

With Modric on the sidelines, Real will look to the likes of Mateo Kovacic, Isco and Marco Asensio to fill the void in midfield alongside Kroos while the former Tottenham Hotspur ace makes his recovery.

The Croatia international was a consistent part of Real's starting XI last season and started in 41 of his 44 appearances across all competitions, scoring two goals and recording four assists.

Modric appears likely to miss matchups against Real Betis, Legia Warsaw and Athletic Bilbao, although Zidane will count his blessings that the upcoming international break will limit the impact of his star's absence.