Sporting are third in Group F by virtue of a lone win against Legia Warsaw, while they lost in all their remaining three matches so far. There is a five-point gap between them and Real on second place, which means anything less than a win here will eliminate them from the group stage.
At the same time, a home win can only give them the slightest hopes as Real Madrid must not get a point from their final group game against Borussia Dortmund.
Real were given a big scare when they met Sporting at the Santiago Bernabeu. The Portuguese side took a shock lead in the second half and look set for all three points until Ronaldo came to haunt his childhood club. An 89th minute free-kick goal from the Real Madrid ace levelled the scores before Alvaro Morata scored the winner with seconds left on the clock to complete a 2-1 win for the Los Blancos.
Sporting, however, went on to defeat Legia Warsaw 2-0 at home before losing both home and away leg to Borussia Dortmund. While Real were held to a 2-2 draw by Dortmund, which was backed up by a brilliant 5-1 win at home against Legia. However their trip to Warsaw end in tatters as Legia came back from two goals down to earn a 3-3 draw.
Madrid are now second in the group with eight points from their two wins and two draws. A draw here will confirm their entry into the round of 16. Borussia Dortmund on the tip of the table have 10 points, they do will qualify with a draw or a Sporting defeat. Legia at the bottom of the table with one point are already eliminated.