Ones to watch in the group stage

Group A

Saúl Ñíguez (Club Atlético de Madrid)
After returning from a successful loan spell at Rayo Vallecano de Madrid, the 19-year-old central midfielder has been compared to fellow academy graduate Koke by boss Diego Simeone.
Kingsley Coman (Juventus)
After the huge success of Paul Pogba, Juve hope Coman, another young Frenchman, can repeat the trick. Lured this summer from Paris Saint-Germain, the 18-year-old forward was arguably man of the match in the Serie A opener at AC Chievo Verona.
Isaac Thelin (Malmö FF)
The 22-year-old front man scored away against both FK Ventspils and AC Sparta Praha in UEFA Champions League qualifying after joining from IFK Norrköping in mid-July, as well as on his debut for the Sweden Under-21s.
Jorge Benitez (Olympiacos FC)
Crossing the Atlantic from Club Guaraní, Paraguay forward Benitez, 22, may be set for great things if he can adapt quickly to European football. It will help that Olympiacos's system is aimed at constantly feeding the central striker from the flanks.

Group B

Raheem Sterling has impressed for Liverpool©AFP/Getty Images

Luca Zuffi (FC Basel 1893) 
The 24-year old has long been talked about in Switzerland, if not outside. Signed from FC Thun in July, he will help Basel with his confidence on the ball and strategic thinking in central midfield. It may not be long before all of Europe knows his name.
Raheem Sterling (Liverpool FC)
The England winger's lightning pace and cool head in the penalty box make him a terrific asset for a Liverpool side adjusting to life after Luis Suárez. Anfield regulars will hope the 19-year-old's understanding with Daniel Sturridge continues to flourish in the coming campaign.
Georgi Terziev (PFC Ludogorets Razgrad)
A Bulgarian champion in his first season with Ludogorets, the centre-back is growing with every game. He was solid against FC Steaua Bucureşti over both legs of the play-off success and is learning fast playing alongside Cosmin Moţi.
Jesé Rodríguez (Real Madrid CF)
After suffering a season-ending knee ligament injury during the round of 16 second leg against FC Schalke 04 last term, the 21-year-old forward will seek to vindicate Carlo Ancelotti's decision not to bring in a back-up for Karim Benzema.

Group C

Geoffrey Kondogbia (AS Monaco FC)
A 2013 FIFA U-20 World Cup winner with France and already a full international, Kondogbia was enticed from Sevilla FC last season and proved he has all the talent to shine in the group stage. The ex-RC Lens trainee, now 21, is among the best box-to-box midfielders in Ligue 1.
Vladlen Yurchenko (Bayer 04 Leverkusen)
With teenagers Julian Brandt and Levin Öztunali having sampled first-team football last term, Yurchenko could do so this campaign. The 20-year-old Ukrainian attacker – a summer arrival from FC Shakhtar Donetsk – caught the eye in pre-season, netting in each of his four outings.
Ivan Solovyev (FC Zenit)
At 21, Solovyev is considered one of the brightest stars of the new generation in Russia. The FC Dinamo Moskva academy product landed at Zenit in summer 2013 and intends to prove his worth at the highest level after a brief loan stint with FC Amkar Perm.
Talisca (SL Benfica)
Benfica have high hopes for the lanky 20-year-old, a summer recruit from Brazilian club EC Bahia. He can play in midfield or behind a striker and has already caught the eye with his speed, passing efficiency and powerful left foot.

Pierre-Emerick Aubameyang has settled at Dortmund©Getty Images

Group D

Calum Chambers (Arsenal FC)
A graduate of Southampton FC's academy and newly capped by England, the 19-year-old arrived in the summer expecting to be Arsenal's second-choice right-back – yet immediately slotted into central defence. Showing flexibility, a reading of the game and a calm head, he has ensured he will feature prominently this term.
Pierre-Emerick Aubameyang (Borussia Dortmund)
It may sound strange to forecast a breakthrough for a 25-year-old striker who claimed 16 competitive goals in the last campaign. However, the former AS Saint-Étienne attacker seems more settled now, having been criticised in the past for the defensive side of his game.
Bruma (Galatasaray AŞ)
A €10m buy from Sporting Clube de Portugal 12 months ago, Bruma missed the second half of last term after knee surgery. His belief and physicality now restored, the 19-year-old will likely be used by Cesare Prandelli as a left-winger, given his potential to impress at this level.
Youri Tielemans (RSC Anderlecht)
A senior debutant on the first day of last season, less than three months after his 16th birthday, he went on to figure in 29 Eerste Klasse games. The gifted midfielder became the youngest Belgian to appear in the UEFA Champions League, and the third most junior ever, when starting against Olympiacos FC last October.

Group E

Juan Manuel Iturbe (AS Roma)
Iturbe's first season in Italy with Hellas Verona FC brought not only eight goals in 33 games but glimpses of brilliance to suggest the diminutive forward can become a real star with his speed and technique. Roma promptly came calling for the 21-year-old Argentinian.
Pierre Højbjerg (FC Bayern München)
Højbjerg featured in a few matches towards the end of last term and is expected to have regular starts this season. The Denmark midfielder, 19, praised by Josep Guardiola for his determination and versatility, is widely touted as the next academy graduate to make it on the big stage.
Eliaquim Mangala (Manchester City FC)
Boasting plenty of European experience after three seasons with FC Porto, the 23-year-old French international is being heralded as Vincent Kompany's central-defensive partner for the long term. Quick, strong and dominant in the air, he will be a key cog as City aim to crack the UEFA Champions League.
Vitinho (PFC CSKA Moskva)
Great expectations surrounded the Brazilian forward – a quick, proficient dribbler who can shoot with either foot – following his August 2013 transfer from Botafogo FR. Though he failed to score in 18 outings in all competitions last term, the 20-year-old opened his account on the first day of 2014/15, suggesting he has finally found his feet. 

Serge Aurier (centre) joined Paris this summer©Getty Images

Group F

Ricardo Kishna (AFC Ajax)
After a knee injury stalled his development for two years, Kishna broke into the Ajax first team in the second half of last season. This term the winger, 19, has been heavily involved in coach Frank de Boer's plans from the off.
Marios Antoniades (APOEL FC)
The 24-year-old Cyprus player, a product of APOEL's academy, became a regular last term under coach Giorgos Donis after being switched to the left of defence despite starting out as a centre-half. His impressive contribution resulted in him making the left-back berth his own.
Rafinha (FC Barcelona)
The versatile, fleet-footed midfielder has all the tools to become the most impressive graduate of La Masia since brother Thiago Alcántara. The 21-year-old shone last season under Luis Enrique while on loan at RC Celta de Vigo.
Serge Aurier (Paris Saint-Germain)
Right-back Aurier's first-team experience with Lens and Toulouse FC belies his 21 years, with Paris now earmarking him to replace Olympique Lyonnais-bound Christophe Jallet. The Ivory Coast international, a standout at the FIFA World Cup in Brazil, may be a revelation of the group stage.

Group G

Kurt Zouma (Chelsea FC)
Bought for €14m-plus from St-Étienne last January but immediately loaned back to his original club to see out the season, the highly-rated Zouma – 19 and a France U21 regular – has now been handed the No5 shirt at Stamford Bridge.
Max Meyer (FC Schalke 04)
Great things are expected of a player who turns 19 in the first matchweek – and rightly so. The home-grown midfielder followed up his 30 Bundesliga appearances in 2013/14 with a first Germany cap against Poland in May. Meyer may even be given the playmaking position.
Petar Stojanovič (NK Maribor)
The 18-year-old was ever present for the Slovenian champions in qualifying. Yet Stojanovič had already made his mark for the club as the youngest debutant in Slovenia's top flight, in March 2012. Nominally a midfielder, the teenager is also a very dependable defender, usually down the right.
Naby Sarr (Sporting Clube de Portugal)
Marcos Rojo's departure to Manchester United FC could be the chance for towering central defender Sarr to impress. A summer signing from Lyon – for whom he played just two Ligue 1 games – the powerful 21-year-old won the FIFA U-20 World Cup with France in 2013.

Group H

Rúben Neves scored on his Porto debut©Getty Images

Unai López (Athletic Club)
Ander Herrera's sale to Manchester United FC has opened a gap for a new star at San Mamés – and everyone at the Basque club is convinced that their 18-year-old attacking midfielder is the man to fill the void.
Ilya Aleksievich (FC BATE Borisov)
The 23-year-old Belarusian international has the makings of a supremely talented central midfielder. He is not particularly tall but, thanks to his good positioning and intellect, he contributes both in attack and in defence.
Rúben Neves (FC Porto)
The defensive midfielder repaid coach Julen Lopetegui's faith by becoming Porto's youngest Liga scorer at 17 years and 155 days with an opening-day goal against CS Marítimo – on his competitive debut. Neves got a further vote of confidence by starting both play-off legs against LOSC Lille.
Ivan Ordets (FC Shakhtar Donetsk)
Back after spending much of the past two campaigns loaned to FC Illychivets Mariupil, the totemic 22-year-old centre-back is tipped to become the main man for Shakhtar and the Ukrainian national team in future years.