All or nothing for Sociedad in Champions League bout

Atlético Madrid and Barcelona can take it easy as the Champions League comes around again. Both Liga sides have already qualified and Diego Simeone confirmed ahead of time that he will be leaving half his first team in Madrid for the chilly trip to play Zenit Saint Petersburg (Tuesday, 6pm, Canal + Liga de Campeones). Also on Tuesday, Gerardo Martino can also rest some of his weary stars for the visit of Ajax (8.45pm, La 1) — a chance to regroup ahead of a glut fixtures between now and the winter break.

For Real Sociedad though, Wednesday's trip to play Ukranian champion Shakhtar Donetsk at the Donbass Arena (8.45pm, Canal + Liga de Campeones) is the most important game of the Basques' season to date. La Real chalked up its first point of the tournament in holding Manchester United last time out, and must win this match to stand any chance of reaching the knockout stages. Herein lie two problems. First, with two games to play, La Real already needs a favor: United to beat Bayer Leverkusen away. Second, the Brazilian-laced Shakhtar requires just a point to be assured of third place and the crumb of comfort offered by the Europa League; a tie would also leave it poised for the next round whatever the result in the BayArena.

In Sociedad's favor, Shakhtar has gone four Champions League games without a home win — although three of those results were stalemates. If La Real plays with the skill and determination it displayed in the 4-3 win over Celta at the weekend, anything is still possible.

Matters for Real Madrid are considerably more comfortable, even in the absence of eight-goal Cristiano Ronaldo, who pulled a muscle against Almería at the weekend. Top of the group with 10 points, a tie will suffice to guarantee going through as group winner when Galatasaray visits the Bernabéu (8.45pm, Canal + Liga de Campeones). Even defeat in Wednesday's battle could result in victory in the wider engagement if Juventus, bottom of the group on three points, beats Copenhagen in Turin. The loss of Ronaldo is mitigated by the return of Marcelo, who was instrumental in Real's 6-1 destruction of the Turks in Istanbul, and Ángel di María, who will likely occupy his habitual right-flank berth to allow Gareth Bale to patrol the left.