Darren Fletcher is the most notable omission from Manchester United's 25-man Champions League squad, suggesting the Scotland captain is still battling to return to first team action before the end of the year.
The tenacious midfielder has fought long term illness in ulcerative colitis that has seen him take two prolonged spells away from football over the past two years and threatened to force him into early retirement all together.
Sounds emitting from Old Trafford over the summer have suggested Fletcher will be ready to return to action in the coming months after being limited to just 13 appearances for the club since November 2011.
But despite United's midfield falling under scrutiny even with the addition of Marouane Fellaini, the club will not risk Fletcher's long term health with another premature return.
Fletcher admitted in August he didn't expect to be involved at the start of David Moyes' reign as United boss, but his omission from the group stages of the competition suggest the midfielder may struggle to return before 2014.
On a more positive note, the 29-year-old has been named in David Moyes' 25-man Premier League squad, suggesting the midfielder will have a role to play in United's defence of their domestic crown.
The United midfielder is not the only big name to miss out on their respective Champions League squad; Michael Essien of Chelsea has also been left off his club's list for the competition that begins on the 17 & 18 of September.
The Ghanaian was seemingly given a reprieve at Stamford Bridge by Jose Mourinho, who took him on loan to Real Madrid last season after he fell out of favour with the Blues.
But the 30-year-old has yet to make an appearance this season, starting and finishing the club's four games this season on the bench.
Nicklas Bendtner is a slightly surprising inclusion on Arsenal's Champions League list. The Dane was primed to leave the Emirates during the summer and claimed in a statement earlier this week that the Gunners blocked a deadline day move to an unnamed Premier League club due to Arsene Wenger's inability to secure another striker.
The 25-year-old did conclude by saying he will continue to give his all to the Arsenal cause, and could be looked upon to prove so during the group stages of the tournament.
Champions League 25-man squads:
Arsenal: Szczęsny, Sagna, Mertesacker, Vermaelen, Koscielny, Rosický, Arteta, Podolski, Wilshere, Özil, Giroud, Viviano, Walcott, Oxlade-Chamberlain, Ramsey, Monreal, Cazorla, Flamini, Fabiański, Sanogo, Jenkinson, Gibbs, Ryo, Bendtner. Zelalem
Chelsea: Cech, Schwarzer, Ivanovic, Cole, Luiz, Cahill, Terry, Azpilicueta, Bertrand, Ramires, Lampard, Oscar, Mikel, De Bruyne, van Ginkel, Hazard, Willian, Torres, Mata, Schurrle, Ba, Eto'o
Manchester City: Hart, Pantilimon, Johansen, Richards, Kompany, Zabaleta, Lescott, Kolarov, Clichy, Demichelis, Nastasic, Boyata, Milner, Nasri, Garcia, Navas, Rodwell, Silva, Fernandinho, Toure, Negredo, Dzeko, Aguero, Jovetic
Manchester United: De Gea, Lindegaard, Rafael, Evra, Jones, Ferdinand, Evans, Smalling, Vidic, Fabio, Buttner, Anderson, Giggs, Carrick, Nani, Young, Cleverley, Valencia, Kagawa, Zaha, Fellaini, Rooney, Hernandez, Welbeck, van Persie
Celtic: Forster, Zaluska, Izaguirre, Ambrose, van Dijk, Wilson, Mulgrew, Mouyokolo, Lustig, Biton, Brown, Commons, Ledley, Rogic, Samaras, Stokes, Boerrigter, Balde, Pukki