Wayne Rooney, James Rodriguez and Nabil Fekir are among the stars expected to be missing when the Champions League group stage kicks off on Tuesday and Wednesday.
To get you up to speed on the team news ahead of the opening fixtures, Goal takes a match-by-match look at the injuries and suspensions currently troubling the competition’s 32 clubs.
Zlatan Ibrahimovic is expected to return to the Paris Saint-Germain team to face his former club Malmo after being rested for Friday night’s Ligue 1 match against Bordeaux.
Laurent Blanc confirmed the Swede was ready to play in the 2-2 draw but opted to keep him out of the squad after his appearance for Sweden in the European Qualifiers three days earlier.
Javier Pastore also missed the Bordeaux match but, like Ibrahimovic, trained over the weekend after a calf injury and although he is not expected to start, he could make the bench.
Malmo will be without their own Zlatan – Zlatan Azinovic – who is out for the season with a knee injury, while Agon Mehmeti is a doubt with a foot problem and Oscar Lewicki has a cold.
Danilo and James Rodriguez will miss out for Real Madrid, with both expected to be sidelined for at least a month with their respective foot and thigh injuries.
Otherwise new manager Rafa Benitez should have a full selection to choose from. Shakhtar are likely to be without Facundo Ferreyra, who is recovering with an individual training plan, but Ivan Ordets is back in contention.
Wayne Rooney missed Manchester United’s victory over Liverpool and is unlikely to return in time for their Champions League Group B opener after suffering a hamstring injury in training.
Phil Jones (calf) did not feature on Saturday and will not travel despite returning to training, but Andreas Pereira is back in the squad.
PSV will test midfielder Adam Maher‘s fitness ahead of kick off – he missed the 6-0 victory over Cambuur on Saturday – while Jetro Willems and Florian Jozefzoon are out with knee injuries.
Vieirinha missed Wolfsburg’s weekend league match against Ingolstadt after being injured while on international duty with Portugal and is a doubt again.
Goalkeeper Koen Casteels has also been struggling with a toe problem so Diego Benaglio will continue in goal after returning from a back injury.
CSKA Moscow travel to Germany with a 20-man squad, with only B-list players Ilya Pomazun, Nikita Chernov and Aleksandr Makarov left at home.
Eduardo Salvio suffered a serious knee injury at the end of last season and will be sidelined for some time yet for Benfica.
Astana, making their group-stage debut, are missing suspended striker Patrick Twumasi, who was sent off in the third qualifying round.
Atletico Madrid will be without left-back Filipe Luis, who is struggling with a minor leg injury and does not travel despite taking part in training on Sunday.
Galatasaray are missing experienced duo Hamit Altintop and Aurelien Chedjou.
Manchester City are waiting on the fitness of key players Sergio Aguero, Raheem Sterling and David Silva. Aguero was substituted with a knee injury against Crystal Palace at the weekend, while Sterling and Silva missed out entirely.
Manuel Pellegrini is hopeful, however, that all three could return, with Sterling recovering from a hamstring strain and Silva knock to the ankle.
Fernando is close to a comeback from a groin problem but fellow midfielder Fabian Delph (hamstring) is definitely out. Gael Clichy (ankle) and Pablo Zabaleta (knee) are not expected to be back until October.
Claudio Marchisio (abductor) lasted only 45 minutes on his return to the Juventus team and is out again, while Sami Khedira and Kwadwo Asamoah remain out with respective thigh and knee injuries.
Unai Emery faces a selection dilemma at centre-back with Adil Rami (adductor), Nicolas Pareja (knee) and Daniel Carrico (hamstring) all currently sidelined.
Winger Gael Kakuta is also out for Sevilla with an abdominal problem despite making the team on Friday night against Levante.
Gladbach are missing Fabian Johnson, who has a torn calf muscle, Patrick Herrmann, who is out with a knee problem and Martin Stranzl, who suffered an eye injury against Hamburg on Friday.
New signing Charles Aranguiz is a long-term absentee for Bayer Leverkusen with a torn Achilles’ tendon, while Omer Toprak is also out with a torn thigh ligament.
Tin Jedvaj is back in training but this match is likely to come too soon for him and Roberto Hilbert is also a doubt in defence with a knee problem.
Alexander Hleb was substituted as a precaution for BATE against Shakhtyor on Saturday but is expected to start.
Thomas Vermaelen will be sidelined once again after suffering a calf injury against Atletico Madrid, whileClaudio Bravo is also out with a similar problem.
Dani Alves continues to recover from a groin strain so Sergi Roberto will continue at right-back. New signings Aleix Vidal and Arda Turan are not eligible to play for Barcelona until the New Year.
Miralem Pjanic will miss around three weeks of action with a calf injury of his own, while long-term injury victim Kevin Strootman is recovering from surgery on his knee.
Young defender Elio Capradossi has had his rise into the senior squad halted by a knee ligament injury sustained while playing for Italy’s Under-20 side.
Tomas Rosicky and Danny Welbeck are unlikely to play again this year due to knee injuries, while Jack Wilshere is waiting to discover if he needs surgery on a cracked fibula.
Dinamo are without defender Gordon Schildenfeld, who is yet to play this season, while Goncalo Santosis suspended after being sent off in the final qualifying round against Skenderbeu.
As was the case during last season’s Champions League, Bayern Munich once again have a number of injury problems to deal with.
Star wingers Franck Ribery and Arjen Robben will both miss this match with respective ankle and groin problems, but Mario Gotze should be fit after a muscle injury.
Mehdi Benatia (hamstring) has been out since August and though Holger Badstuber and Jan Kirchhoffare nearing returns from long-term injuries, all three centre-backs remain unavailable.
Andreas Bouchalakis is back in training but remains doubtful for Olympiakos after a quadiceps injury, while Luka Milivojevic is suspended.
Thibaut Courtois is not expected to return for Chelsea until December after undergoing knee surgery, so Asmir Begovic will continue to deputise in goal.
Oscar is expected to be in contention for a place in the squad after a knee injury of his own, but Bertrand Traore is likely to miss out with a hip injury suffered during the international break.
Porto coach Julen Lopetegui will have the benefit of choosing from a fully fit squad to for the trip to Ukraine to face Dynamo Kiev.
Serhiy Sydorchuk and Lukasz Teodorczyk are both expected to miss out for Dynamo but Aleksandar Dragovic, who was rested against Oleksandria at the weekend, should be back.
Sergi Darder is still building up his fitness following his move from Malaga and may not feature for Lyon, while Clement Grenier (quadriceps) remains sidelined but has returned to training.
Nabil Fekir is a long-term absentee, with the young Frenchman facing a lengthy spell on the sidelines with a cruciate ligament injury. Injury-plagued Gueida Fofana is also out.
Gent manager Hein Vanhaezebrouck is short of centre-backs, with Erik Johansson, Rami Gershon andUros Vitas all out, but Stefan Mitrovic returned from the bench in the 1-1 draw with Zulte Waregem.
Valencia goalkeeper Mathew Ryan (knee) has been ruled out until October and Diego Alves (ACL) remains out, so Jaume is likely to continue between the sticks.
Santi Mina is also out with a sprained ankle while Zenit had Oleg Shatov come through 74 minutes of their 2-2 draw with CSKA Moscow despite not training.