If he's looking for omens as to whether Chelsea will go all the way in the competition, Jose Mourinho may just have one in the group stages after the Blues faced both Basel and Steaua en route to lifting the Europa League trophy last season.
Then again, when Chelsea last faced Schalke in the group stages, Mourinho quit as Chelsea coach before he had the opportunity to lead his out against the Germans.
Chelsea were on the losing side in their first leg of the Europa League quarterfinal against Steaua last term, a Raul Rusescu penalty giving the home side a 1-0 victory. But they soon turned things around at Stamford Bridge, winning 3-1 to advance courtesy of their superior aggregate score.
It was a little more straightforward in the Europa League semifinal against Basel. The Blues won 2-1 in the first leg in Switzerland after David Luiz fired home a 90th-minute free-kick, while back home in London a convincing 3-1 saw them reach the final.
In 2013-14, it's a different ballgame, however, so the Blues will need to be back to their best to ensure they avoid last year's disappointment of being knocked out in the Champions League group stages.
Schalke, Steaua and Basel carry their own threats, so Bleacher Report has highlighted three players who could cause Chelsea some problems when the Champions League gets underway in mid-September.
Basel: Marco Streller
The season is only six games old in Switzerland, but there is an unfamiliar feel to things at the top of the table.
Basel, Swiss champions for the past four seasons, currently sit in fourth place, six points behind leaders Young Boys.
It's not exactly a crisis, but Murat Yakin's side will be eager to close the gap over their rivals sooner rather than later to avoid it getting any bigger as the season wears on.
With Marco Streller in their ranks, that will be more than possible.
The 32-year-old has scored three goals in his four appearances this term, and had it not been for a thigh injury suffered earlier this month, he would probably have more to his name.
He's currently in his second spell at the club, having departed in 2004 for Stuttgart before returning to St. Jakob-Park three years later.
The Swiss international is the main source of goals for Basel and will pose a considerable threat.
Streller may not have found himself on the scoresheet against Chelsea in the Europa League last season, but he caused problems at the back for the Blues that will mean John Terry and Co. keeping a close eye on him.
Steaua Bucharest: Cristian Tanase
Win their two games in hand and Steaua Bucharest will reach the summit of the Romanian league once more this season.
As with the rest of Europe's leagues, it's still very early, but despite being slightly off the pace, there is a sense Steaua will take control in the coming months—just as they did last season when claiming their first league title in seven years.
One of those who stands out is Cristian Tanase, an attacking midfielder who is one of the main schemers in this Steaua outfit.
The 26-year-old has also become a key part of the Romanian national team, making over 25 appearances for his country since making his debut in 2008.
He's not shy of confidence, either, proudly wearing the No. 10 shirt once donned by Romanian legend Gheorghe Hagi. If Tanase performs anywhere near the level of his predecessor in the Champions League this term, Chelsea could very well have a problem on their hands.
Schalke: Julian Draxler
Getting one point from the opening three games into the new Bundesliga season, Schalke are going to find it difficult to qualify for the Champions League again in 2014-15 if they continue in that vein of form.
There's no need to look that far ahead yet. Jens Keller's side have an intriguing Group E to negotiate in the present, but in truth, with respect to their opponents Basel and Steaua Bucharest, Schalke should give Chelsea the biggest challenge for top spot.
Dutch ace Klaas-Jan Huntelaar is probably the first name that jumps out at observers when considering Schalke's danger men. Adam Szalai is enjoying a productive season alongside him in attack, too, scoring twice already.
However, Julian Draxler is a player that will cause plenty of teams problems at home and abroad this year.
Apparently the 19-year-old has been coveted by Chelsea this summer, with The Express claiming Schalke have put a £60 million price tag on him to deter the Blues—and the host of other clubs rumored to be admirers—from bidding.
Not only can he grab assists for teammates, drawing attention from opposing defenders around him to create space for others, Draxler also has a wonderful long-range shot.
He scored in this week's 3-2 win over PAOK Salonika in the Champions League playoffs, grabbing an assist also as Schalke ran out 3-2 winners in Greece and 4-3 on aggregate.
We should expect more from him, and if he delivers, expect that price tag to rise a little.
Garry Hayes is Bleacher Report's lead Chelsea correspondent and will be following the club from a London base throughout the 2013-14 season. Follow him on Twitter here @garryhayes