"I think most people would say they were certainly one of the toughest teams we could’ve got on paper."- Frank Lampard
Clearly, Chelsea's former head coach Frank Lampard was under no illusions after his side's name followed Atlético Madrid's out of the hat in the Champions League last 16 draw back in December.
It is difficult to argue with him considering the likes of Porto and Borussia Monchengladbach were possible opponents while Atléti top La Liga, but equally some enigmatic recent form means that both sets of supporters will be feeling somewhat uncertain about the magnitude of the challenge facing their team when the first leg kicks off on Tuesday night.
Their European record is finely balanced, with two wins each and three draws between them.
So, what does history dictate might come to pass? Both clubs represent modern success stories in European competition, and it's fair to say their encounters have been entertaining.
Here is a look back at Chelsea's head-to-head record with the side from the Spanish capital.
1. Chelsea 4-0 Atletico - October 2009
With Carlo Ancelotti installed at the helm, Chelsea started this game with a ludicrous midfield of Lampard, Michael Essien, Michael Ballack AND Deco.
Lampard scored as the two clubs' first meeting ended in a 4-0 thumping back in the Champions League group stage of 2009.
Salomon Kalou also got in on the action with a brace, although Atléti were no mugs themselves with Diego Forlán and a certain Sergio Agüero leading the line.
Neither of them were a touch on the legendary Ivorian that night, though.
2. Atletico 2-2 Chelsea - November 2009
The return fixture of that season's group phase was inevitably a tougher proposition in a raucous Estadio Vicente Calderon.
Goalless at half-time, the second period would be dominated by now-Premier League legends Didier Drogba and Agüero.
The latter opened the scoring off the bench with a rifled volley, before Drogba - who had missed the opening three group games with a ban for the whole 'IT'S A F***ING DISGRACE!' thing the season prior - scored a late brace that seemed to have nicked it for the Blues.
His Argentine adversary would have the final say, though, curling home a wonderful last-minute free kick to send the Rojiblancos faithful into raptures.
3. Chelsea 1-4 Atletico Madrid - August 2012
Anyone who watched this UEFA Super Cup final live will rarely have witnessed such a masterclass in finishing.
Atléti's latest South American hotshot Radamel Falcao produced a sublime first-half hat-trick, making Roberto Di Matteo's hapless Chelsea side look more like Johnstone's Paint Trophy winners than European champions.
First a cute dink over Petr Cech that kissed the post on its way in, then a lovely left-foot curler into the top corner, and finally a perfect first touch beyond Ashley Cole and a prod past the keeper.
Unfortunately it was a performance that set the tone for a naff start to the season for the Blues.
4. Atletico Madrid 0-0 Chelsea - April 2014
Not much to report from this typically cagey Champions League semi-final first leg.
Then-boss José Mourinho probably felt it was a decent result at the time, but Chelsea would ultimately pay the price for not getting any away goals in Madrid...
5. Chelsea 1-3 Atletico Madrid - April 2014
Perhaps the match that convinced the west London club to splash £32m on Diego Costa that summer.
Despite Fernando Torres giving the hosts the lead, Atléti came back with a vengeance, producing a stunning counter-attacking display and ending up comfortable victors at Stamford Bridge.
Typically fiery in his display, bullish striker Costa converted a penalty to make it 2-1 and seal the deal on the hour mark, but Chelsea fans would eventually forgive and forget.
A wonderful overhead kick from Olivier Giroud gave Chelsea a 1-0 away win over Atletico Madrid, in the first leg of the pair's Champions League round of 16 tie.
We preview this week's two Champions League round of 16 first leg ties along with the second legs of the Europa League's first knockout round
Atletico Madrid face Chelsea in the first leg of their Champions League round of 16 tie on Tuesday evening. It's taking place in Bucharest.
Predicting the Chelsea lineup to start in the Champions League against Atletico Madrid, with Mason Mount, Olivier Giroud, Tammy Abraham & more.
6. Atletico Madrid 1-2 Chelsea - September 2017
The one result on this list that should give Chelsea the most encouragement, especially given its recency.
In an increasingly rare European masterclass from Antonio Conte, the Blues came from behind to become the first English side to beat Atlético away from home, and the first visiting winners at the brand new Wanda Metropolitano.
Two of the club's recent flops up top got the job done, with Alvaro Morata equalising before Michy Batshuayi tapped home with 94 minutes on the clock. Scenes.
7. Chelsea 1-1 Atletico Madrid - December 2017
The two sides' most recent meeting came at Stamford Bridge in the reverse fixture of the 2017 Champions League group stage.
Both teams needed a win in the final game to revive mediocre campaigns to that point, so of course it ended in a draw.
Chelsea finished second to Roma and, just as was the case when the pair were in the same group in 2009/10, Atléti would drop into the Europa League and win it.