Previous European Cup/CL best: Winners: 2012
Manager - Jose Mourinho: He may have won the Champions League with Porto and Inter Milan, but it will grate on Mourinho that he has never lifted the trophy during his two stints with Chelsea. Under his management, the Blues have never in fact gone beyond the semi-final stage. Having spent big in the summer, the 51-year-old will no doubt have his sights set firmly on Europe's top club competition, as well as the Premier League title.
Key Player - Cesc Fabregas
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Diego Costa's early season form in front of goal has quite rightly dominated the headlines as far as Chelsea are concerned, but without Fabregas loading the bullets for him, the Spanish striker would not have had the opportunities to show just how clinical he is. After four rounds of Premier League matches, the creative midfielder has set up six goals for his teammates. Take him out of the starting lineup and all of a sudden Costa could cut an isolated figure. Fabregas's ability to carve open a defence will prove crucial during the latter stages of the competition.
Sports Mole says: Providing that key players remain fit and in form, Mourinho and his charges will be confident that they can go deep this year. As with so many sides, a lot will depend on the luck of the draw, but no team will want to face Chelsea. There is certainly nothing in the group that should worry the West Londoners, who should romp through as winners.
Did you know?: In the last 10 years, Chelsea have appeared in seven Champions League semi-finals, but have only progressed through to the final once.
Previous European Cup/CL best: Semi-finals: 2011
Manager - Jens Keller: It would be fair to say that Keller has not always been the most popular of head coaches among the Schalke faithful, but he earned himself some brownie points last term by guiding the club to third in the Bundesliga and automatic qualification for the Champions League. This will be the 43-year-old's first major involvement in the Champions League as a manager and one that he will no doubt be hoping that his side can extend into the knockout stages.
Key Player - Benedikt Howedes
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Such is the esteem that Howedes is held in by Germany boss Joachim Low, he was one of only three players along with Manuel Neuer and Philipp Lahm to have played in every minute of his nation's triumph at this summer's World Cup in Brazil. Although by no means a flashy defender, the 26-year-old provides a solid and versatile influence, so much so that he is Schalke's captain. The Royal Blues may have attacking talents such as Julian Draxler and Klaas-Jan Huntelaar, but Howedes's impact defensively should not be ignored.
Sports Mole says: While there were easier opponents in pot one than Chelsea, Schalke would have been aware that they were likely to get a tough opponent in their group either way. The other two sides, though, are more than beatable. Sporting should provide the sternest test, but Keller and his men will be bitterly disappointed if they are not in the hat for the last 16.
Did you know?: Ten German clubs have featured in the Champions League era, with Schalke being the eighth of those.
Previous European Cup/CL best: Group stages: 1999
Manager - Ante Simundza: The 42-year-old will forever be remembered by Maribor supporters for the goal that he scored that defeated Dynamo Kiev in the Champions League in 1999. He seems to have taken that knack into management, having guided the club to their fourth consecutive Slovenian league title last term. However, they were surprisingly defeated by Gorica in the cup final.
Key Player - Marcos Tavares
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The former Brazil youth international was the hero of the playoff clash against Celtic - a game in which he scored the winning goal to secure his side's passage through to the group stages for only the second time in their history. Having joined Maribor back in 2008, Tavares has become the club's leading goalscorer of all time.
Sports Mole says: If everybody connected with Maribor were to be totally honest, they are just happy to be in the Champions League, particularly with the financial rewards that the competition provides. Qualification for the next round looks to be beyond the Purples, but with a bit of good fortune, they could challenge Sporting for third spot and a place in the Europa League.
Did you know?: Maribor are the only club from Slovenia to have participated in the Champions League.
Previous European Cup/CL best: Last 16: 2009
Manager - Marco Silva At the age of 37, it was somewhat of a surprise when Sporting plumped for Silva to replace Monaco-bound Leonardo Jardim at the helm. However, he had displayed his credentials during his three-year stint in charge of Estoril. Under his management, Estoril qualified for the Europa League for the first time in their history, while earlier this year they inflicted a first home defeat on Porto since 2008.
Key Player - William Carvalho
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Such has been Carvalho's rise over the last two years, that the big clubs are thought to be circling. The likes of Arsenal and Manchester United are said to have watched the 22-year-old on numerous occasions last term and are expected to continue their pursuit of him in January. Carvalho is an athletic midfielder that has unrivaled stamina. If he goes on to produce the goods in the Champions League, he might not be a Sporting player for much longer.
Sports Mole says: If anyone is going to challenge Schalke for second spot, it will be Sporting. Their home form will be key, particularly the clash against their German counterparts, while it is vital that they collect six points from the two meetings with Maribor. It wouldn't be a surprise, though, if they finished third.
Did you know?: Sporting have not featured in the Champions League group stages since 2008.
Group G fixtures
Wednesday, September 17
Chelsea vs. Schalke
Maribor vs. Sporting
Tuesday, September 30
Sporting vs. Chelsea
Schalke vs. Maribor
Tuesday, October 21
Schalke vs. Sporting
Chelsea vs. Maribor
Wednesday, November 5
Sporting vs. Schalke
Maribor vs. Chelsea
Tuesday, November 25
Schalke vs. Chelsea
Sporting vs. Maribor
Wednesday, December 10
Chelsea vs. Sporting
Maribor vs. Schalke
Prediction: 1. Chelsea 2. Schalke 3. Sporting 4. Maribor