FC Schalke 04 - Manchester United
Schalke 04 and Manchester United will clash for the first time ever in a competitive match.United have conceded just three goals in the competition this season, less than every other team except Real Madrid, who have conceded also conceded three.
The Red Devils are yet to concede a single goal away from home in the Champions League this season.
Schalke are unbeaten in nine Champions League games (seven wins, two draws).
Manchester have lost just one of their last 22 away games in the Champions League (14 wins, seven draws).
Schalke have won all five home games in this season's Champions League.
United are unbeaten in 11 Champions League games (eight wins, three draws), but their last defeat came on German soil, when they went down 2-1 at Bayern Munich just over a year ago.
Raul is currently the Champions League's all-time top-scorer with 71 goals, he is also the only Schalke outfield player to have feature in all 10 of their CL games this season.
United have netted only 12 goals in 10 Champions League games this season, the worst goalscoring record amongst the four semi-finalists.
Ryan Giggs has assisted each of United's last four goals in this competition.
Only Manchester United and Real Madrid are still unbeaten this season in the Champions League.
Real Madrid - FC Barcelona
These teams have met in the Champions League just once before. In the 2001/02 semi-final Real won the first leg 2-0 at the Camp Nou and reached the final after a 1-1 draw at home.Real have won their five Champions League home games this season and haven't conceded a single goal in any of them.
Real Madrid are the only side to have opened the scoring in each of their 10 Champions League games this season.
Barca have lost just one of their last 11 Champions League games (eight wins, two draws).
Since 2009, Barcelona have won only three of their 14 away games the Champions League.
The Catalans have won two of their last three away games in the Champions League (one defeat).
Real are unbeaten in eleven Champions League matches (eight wins, three draws).
Five players have been sent off in the last five meetings between these two sides in all competitions (four for Real and one for Barca).
Real are one of only two sides still unbeaten this season in the Champions League (the other is Manchester United).
The merengues and the blaugrana share the best attacking record of the competition this season, each scoring 24 goals.
Seven of the eight players who have completed the most passes in the Champions League this season play for Barcelona, the only exception is Real Madrid's Xabi Alonso (third) who has completed 656.
Mesut Özil has delivered the most assists in the Champions League this season (seven).