Chelsea, having secured a spot in the last 16 with a match to spare last month courtesy of a 4-0 win over Qarabag in Azerbaijan, were left ruing their Champions League luck on Tuesday night (5 December) after a 1-1 home draw with Europa League-bound Atletico Madrid.

Such a result - which saw Saul Niguez's headed opener cancelled out by an own goal from Stefan Savic - means that the Blues ended the evening as Group C runners-up, level on points with AS Roma with a superior goal difference but behind on head-to-head after blowing a two-goal lead against the Giallorossi in October before slumping to a 3-0 loss in the Italian capital.

Despite manager Antonio Conte's confident assertion that their next opponents "won't be happy to play against us", there is no doubt that not winning the group has majorly dented Chelsea's hopes of avoiding a tough tie in the first knockout phase.

Here, IBTimes UK takes a look at the potential challenges that now lie in store for the 2012 winners and last English team to reach the final...

When and where is the last-16 draw?

The draw begins at 12:00 CET on Monday 11 December and will take place at the Uefa headquarters in Nyon [Switzerland].

Teams Chelsea can draw in Champions League last 16: Paris Saint-Germain, Barcelona, Besiktas

Group winners: Manchester United, Paris Saint-Germain, AS Roma, Barcelona, Manchester City, Besiktas, Tottenham Hotspur, Liverpool

Group runners up: Basel, Bayern Munich, Chelsea, Juventus, Sevilla, Shakhtar Donetsk, FC Porto, Real Madrid

Worst possible scenario for Chelsea: Barcelona/Paris Saint-Germain

This task is made considerably easier by the fact that, owing to four Premier League teams topping their respective groups in Manchester United, Manchester City, Liverpool and Tottenham and another meeting with Roma not permitted at this stage, there are actually only three teams that Chelsea are able to draw as runners-up.

The bad news is that such a restricted lineup means that Conte's side have more than a 65% chance of landing a high-profile last-16 tie against two teams that almost everyone would hope desperately to avoid in Barcelona and Paris Saint-Germain, both of whom would obviously pose an enormous threat to their hopes of qualifying for the quarter-finals.

Ramires and Fernando Torres
Ramires and Fernando Torres both scored during Chelsea's memorable semi-final second-leg draw with Barcelona in 2012 JAVIER SORIANO/AFP/Getty Images

The Catalan giants, whom Chelsea memorably beat to reach the final in 2011-12 despite John Terry's second-leg red card inside the cauldron of the Nou Camp, remain undefeated in all competitions since their Spanish Super Cup loss to Real Madrid in August and currently hold a five-point advantage at the summit of La Liga despite back-to-back draws. Only stalemates away to Olympiacos and Juventus prevented them from claiming maximum points in Group D.

Arguably even more stocked with devastating attacking talent, 13 wins from 16 matches has mega-rich PSG, nine points clear of their nearest domestic challengers, strolling towards a seventh Ligue 1 title and a fourth in five years despite seeing their impressive unbeaten streak recently curtailed by Strasbourg.

The Parisians and Chelsea had become very familiar bedfellows in the Champions League up until the latter's absence last term, facing off in three consecutive seasons after only previously meeting twice more than a decade before. They traded quarter-final and last-16 wins in 2013-14 and 2014-15, while PSG won their most recent clash in 2016 4-2 on aggregate after successive 2-1 victories that both featured goals from Zlatan Ibrahimovic.

Best possible scenario for Chelsea: Besiktas

Chelsea's sole hope for an easier ride - providing they can cope with a typically deafening and intimidating atmosphere inside Vodafone Park - is a tie against Besiktas, who finished ahead of FC Porto, RB Leipzig and AS Monaco in a thoroughly underwhelming Group G.

Turkish champions in back-to-back seasons, Senol Gunes' men currently occupy fourth spot below rivals Galatasaray and Fenerbahce in the Super Lig after winning half of their opening 14 matches, but are only four points adrift of new leaders Istanbul Basaksehir.

Chelsea and Besiktas have met on only two prior occasions, with Sergen Yalcin netting a brace to inflict a first loss of the season on Claudio Ranieri's expensively-assembled outfit in the group stage back in October 2003. Jimmy Floyd Hasselbaink and Wayne Bridge notched late to secure a 2-0 victory two months down the line in the return tie, which was switched to neutral Gelsenkirchen amid security concerns following the bombings in Istanbul.

Jimmy Floyd Hasselbaink
Jimmy Floyd Hasselbaink celebrates his goal against Besiktas in Gelsenkirchen in December 2003 Vladimir Rys/Bongarts/Getty Images