Last season's Champions League flops, Manchester United and Celtic will seek a flying start when they meet in the Group F tie at Old Trafford.
News of all that's transpired on and off the football field.
Real Madrid are on the verge of reaching the King's Cup quarter-finals after winning 3-0 at Numancia on Thursday while holders Barcelona still have work to do after being held to a 1-1 draw at Celta Vigo.
Real Madrid wasted a chance to keep the pressure on the top two in La Liga with a 2-2 draw away to Osasuna where Sergio Ramos was sent off and record signing Gareth Bale substituted.
Twice former winners Benfica came from behind to beat the English side 2-1 to reach the last 16 of the tournament.\nA round-up of Wednesday's matches.
Leading striker Samuel Eto'o will also miss the Champions League Group C match at Udinese because of a bruised ankle.
Barcelona striker Samuel Eto'o finished with 26 goals as he scored in his side's 3-1 defeat at Athletic Bilbao.
Manchester United visit Lille in the Champions League on Wednesday with manager Alex Ferguson under extreme pressure following Saturday's 4-1 thrashing at Middlesbrough.
Zinedine Zidane, Walter Samuel and Michel Salgado will sit out during the match against Real Sociedad
Barcelona beat AC Milan on a 1-0 aggregate, after the second leg semi-final ended goalless.
Arsenal beat Villarreal on a 1-0 aggregate after the second leg semi-final ended goalless.
The Manchester United striker was handed a two-match ban following his sending-off in the Champions League match at Villarreal last week.
Inter Milan coach Roberto Mancini has warned his players against relying on defence when they play Ajax Amsterdam for a place in the quarter-finals on Tuesday.
The Spanish champions went through on 3-2 aggregate after the second leg pre-quarter-final ended 1-1. Juventus and Villarreal also made it to the quarter-finals.
Barcelona earned a valuable 2-1 away win at Chelsea, with the home side playing most of the match with only 10 men.
Inter Milan staged a fierce second-half fightback to draw 2-2 at Ajax Amsterdam.
Werder Bremen scored two late goals to snatch a 3-2 win at home to Juventus and give themselves a chance of making the Champions League quarter-finals.
Villarreal went through to the group stage on a 4-2 aggregate crashing Everton's Champions League.
Ronaldo was named in the Real Madrid squad for Saturday's home league match against Espanyol after a month out with a calf strain.
Atletico Madrid's Brazilian striker Diego Costa scored twice as they came from behind to beat Levante 3-2 at home on Saturday to go three points clear at the top of La Liga.
Struggling Rayo win at Valladolid after late penalty save
Real Madrid striker Ronaldo suffered a recurrence of a calf injury during the 0-0 draw at Villarreal on Sunday.
Villarreal's Brazilian midfielder Marcos Senna tested positive for two banned substances.
Atletico Madrid secured a berth in the Champions League group stage for next season and Deportivo La Coruna narrowly escaped relegation when they came from two goals down to draw 2-2 at champions Barcelona on the final day in La Liga on Saturday.
Marcelino dismissed but Valencia keep pressure on Barcelona
It's been a week now since Real Madrid Cristiano Ronaldo hobbled off the pitch after injuring his thigh against Villarreal during a La Liga match last Wednesday.
The Portugal forward will miss Real's league games against Villarreal, Getafe and Elche but will be available for the King's Cup semi-final, first leg at home to holders Atletico Madrid later on Wednesday and the return game next week.
Messi, who has struggled for form in recent weeks due to a niggling injury, looked on a mission to grab the winner and after twice coming close he completed his treble to put Barca ahead in the 85th minute, reacting quickly to a poor Sevilla clearance to dink the ball over goalkeeper Tomas Vaclik.
Troubled AC Milan were held to a goalless draw by AEK Athens
Diego Forlan, whose fine performances and five goals helped Uruguay finish fourth in the 2010 World Cup, announced his retirement.
Here, Reuters Sport highlights five reasons why last season's double winners have collapsed.