FC Barcelona and Atletico Madrid have vital Champions League matches away from home on Tuesday night.
Barcelona visit Inter Milan and need to avoid defeat following their 2-1 loss away to Bayern Munich in their previous group game.
That defeat means another loss in Milan would suddenly leave Xavi Hernandez's side with a lot of work to do to reach the last 16 of the competition; and Barca's delicate financial situation means they cannot afford to miss out on the knockout stages.
Xavi still has a long list of injuries to contend with, as Ronald Araujo, Hector Bellerin and Memphis Depay all miss out again, but Frenkie de Jong may be able to play, while Sergi Roberto and Eric Garcia are also likely to come into the side. Gavi will also play after suffering a minor injury scare in Saturday's 1-0 win in Mallorca, which took them to the top of LaLiga.
That game saw Alexandre Balde cover at right back, with Jordi Alba on the left and Sergi Roberto's recovery should allow Balde to move back to the left (although that will leave many wondering why Barca signed Marcos Alonso from Chelsea).
Inter are in a difficult moment domestically after suffering consecutive defeats to Udinese and Roma.
Atletico Madrid can't afford any slip-ups either as they travel to face Group B leader Bruges.
The Belgian side has been the surprise package in an even-looking group, containing Porto and Bayern Leverkusen, with two wins from two games, while Atletico need to recover after a tame 2-0 defeat to Bayern Leverkusen last time out.
Diego Simeone's men played well at the weekend as they secured a comfortable 2-0 win away to Sevilla and Simeone recovers Mario Hermoso and Thomas Lemar, who missed out on Saturday.
The coach will be worried by a dip in form from Joao Felix, but Alvaro Morata is in excellent form, while Antoine Griezmann will make his by now traditional 30-minute cameo in the second half.
Bruges' main threat will be Barcelona loanee Ferran Jutgla, who has netted five goals in just six appearances with the club.