IB Times UK identifies the star players from Basel, Schalke and Steaua Bucharest who are looking to inflict more European heartache on Chelsea after the Blues crashed out of the competition at the group stage last season.
Mohamed Salah - Basel
The lightening quick Egypt international was a relatively unknown quantity on the European stage until last season, where his dynamic displays had Tottenham defenders panicked as he tore through them as Basel deservedly knocked the Premier League club out of the Europa League.
The winger-cum-attacking midfielder helped his side claim the Swiss league at a canter and throw themselves back into Champions League contention having progressed through their qualifiers. The 21-year-old twice got himself on the score sheet against English opposition last season against both Tottenham and Chelsea in the Europa League, and Mourinho will have to factor in how to deal with the troublesome Egyptian against a side who have claimed notable upsets against English opposition in recent years.
Basel's previous best Champions League finish: Last 16 (2012)
Julian Draxler - Schalke
With Champions League audiences outside of Germany growing increasingly familiar with the likes of Mario Gotze, Toni Kroos, Maro Reus and Thomas Muller, Julian Draxler is now primed to join that fraternity of technically blessed German attackers from the Bundesliga that delight in Europe's elite tournament.
The 19-year-old signed a new contract with his club during the summer amid interest from Arsenal and Manchester City, demonstrating his unequivocal love for Schalke by claiming he would have to be brainwashed to consider a move to arch rivals Dortmund, who held interest of their own.
Draxler has impressively stepped up to fill the void left by Lewis Holtby after his move to Tottenham last January, honing his role as an archetypical number 10 with commendable class and maturity. Draxler may not be ready to displace his fellow 10s Mesut Ozil and Gotze at international level just yet, but the platform of the Champions League will certainly go some way to testing just what the youngster is capable of.
Schalke's previous best Champions League finish: Semi Finalists (2011)
Federico Piovaccari - Steaua Bucharest
Another of Chelsea's opponents from their Europa League campaign will return to Stamford Bridge before the year is out. The Romanian champions' front line has been boosted this summer by the presence of journeyman Piovaccari, who joined the club on loan from Sampdoria. The 29-year-old has taken to life at the club splendidly, finding the net three times during their battles in qualifying stages of the tournament, including one in either leg of their third round qualifying rounds with Legia Warsaw.
Steaua Bucharest's previous best Champions League finish: Winners (1986)