Europa League Opta Facts - Round of 32 First Leg
Statistics and facts to help your football betting are available every week at William Hill courtesy of Opta Sportsdata, Europe's leading provider of sports performance statistics.
Porto v Manchester City
Porto are the reigning Europa League champions, but won just two of their six games in the Champions League group stages this season.
The Portuguese champions have won only two of their last 14 European matches against sides from England, both coming against Arsenal at home.
Porto have lost four of their last five games against English sides, failing to score in each of these defeats.
Despite winning three of their last four Champions League group stage matches, Manchester City were knocked out and now find themselves in the Europa League.
Excluding qualifying matches, City have been drawn against Portuguese opposition just once before in Europe - in 1970 they faced Académica de Coimbra; drawing their Cup Winners' Cup game away 0-0 before winning 1-0 at Maine Road in the second leg.
Porto last lost a competitive home game on 23rd February 2011 - just under a year ago. This was a 0-1 defeat to Seville at this stage of the 2010-11 edition of the Europa League.
Man City have won just three of their last 10 competitive away games.
Ajax v Manchester United
Excluding qualifiers, Ajax have failed to score in six of their last eight matches in Europe.
The Dutch side have won just one of their last 10 meetings with English sides in Europe (excl. qualifiers); this coming back in 1980 at home against Nottingham Forest.
On the only previous occasion that these two sides were drawn together in Europe, Ajax won the first leg at home 1-0, before losing the second leg 2-0 at Old Trafford.
Manchester United have now scored in 12 successive European matches.
The Red Devils have won five of their last seven matches against Dutch teams in Europe (W5 D1 L1).
The Dutch giants attempted more headed shots than any other side in the Champions League group stages (20).
Ajax have lost three of their last four home games in all competitions.
After a run of seven clean sheets out of eight on the road, the Red Devils have now gone five away games in all competitions without a shutout and have conceded more than once in four of these five games.
The UEFA Cup/Europa League is the only competition Man Utd have played in under Sir Alex Ferguson and not won at least one game.
Stoke City v Valencia
Including qualifiers, Stoke City have won four and drawn one of their five Europa League matches at home so far this season.
In those five games, Stoke have conceded just three goals and scored on each occasion.
Excluding qualifiers, Valencia have won only two of their last nine European matches.
The Spaniards have not won any of their last seven away games in Europe (excl. qualifiers), and have not scored more than once in any of these fixtures.
Valencia are without a win in eight European games against English side (D4 L4) and have only won one of their last 16 on English soil.
Los Che have only netted five goals in their last 13 away European games against English sides and never more than once in a match in this run.
Stoke have never lost on home soil in Europe, winning three and drawing two of five previous games (excluding qualifiers).
The Potters had the best crossing accuracy in the group stages of the Europa League, finding a teammate with 35% of all crosses attempted.