How Real Madrid could line up against Barcelona

Real Madrid are sweating over the fitness of Antonio Rudiger ahead of Wednesday's Copa del Rey semi-final second leg with Barcelona in El Clasico.

The centre-back was unavailable for the weekend's 6-0 La Liga win over Real Valladolid due to knee discomfort, and he will undergo scans on Monday to determine the severity of the problem.

Carlo Ancelotti has expressed his belief that Rudiger has not sustained anything serious, but the quick turnaround makes the German a major doubt for the second leg regardless.

Rudiger could be one of three absentees for Los Blancos at Camp Nou, as Ferland Mendy has sustained a fresh calf problem, while striker Mariano Diaz missed the win over Valladolid with an unspecified issue.

Should Rudiger fail to prove his fitness in time, Eder Militao - whose own goal in the first leg gave Barcelona a 1-0 win - will likely pair up with the returning Nacho Fernandez in front of Thibaut Courtois.

Nacho's return from a ban could push David Alaba into a left-back role ahead of Eduardo Camavinga, while Lucas Vazquez repaid Ancelotti's trust in him with a goal against Valladolid and could also keep Dani Carvajal at bay.

Luka Modric will certainly return in the middle of the park alongside Aurelien Tchouameni and Toni Kroos, as Marco Asensio drops out despite also finding the back of the net at the weekend.

Similarly, Rodrygo came up with a goal and two assists in the drubbing of Valladolid, but a well-rested Federico Valverde should immediately be recalled to the right flank.

Vinicius Junior has been yellow-carded three times in the Copa del Rey this season, but all cautions were wiped at the end of the quarter-finals, so the Brazilian is fine to support Karim Benzema, who netted a seven-minute hat-trick at the weekend.

Real Madrid possible starting lineup: Courtois; Vazquez, Militao, Nacho, Alaba; Kroos, Tchouameni, Modric; Valverde, Benzema, Vinicius Jr