And that's not all! Juventus, who suffered a similar fate as Barcelona, will face Nantes while PSV will lock horns with Sevilla in the upcoming round.

After failing to win their UEFA Europa League group, the biggest fear for Manchester United heading into the knockout round play-offs draw was a possible clash with Barcelona.

The Catalan giants were one of several continental heavyweights that finished third in this season's UEFA Champions League group stage and were thus demoted to Europe's second-tier club competition.

And lo and behold, this is the exact predicament the Red Devils find themselves in as Erik ten Hag's men have drawn Lewandowski and Co. in the upcoming round of the UEFA Europa League.

Given that these are two of the greatest teams to have ever existed, this match-up was always going to spark instant reactions on social media. Many took to Twitter to point out the obvious: two clubs that faced off in UEFA Champions League finals over a decade ago are now battling it out in the Europa League, underlining their recent demise.

Meanwhile, others could not help but get excited over what should be a thrilling encounter between the Premier League outfit and the Spanish side. Check out the best tweets below.

However, Manchester United and Barcelona aren't the only noteworthy sides in this round. Roma, led by iconic manager Jose Mourinho, failed to win their group as well and will now face off against RB Salzburg for a spot in the round of 16.

PSV, on the other hand, just missed out despite beating Arsenal in an impressive 2-0 victory at the Philips Stadion. Now, the Dutch giants must overcome the struggling Sevilla, led by newly-appointed head coach Jorge Sampaoli.

And finally, Juventus, who endured an embarrassing UEFA Champions League campaign, finishing third behind Benfica and PSG, have been pitted against Nantes and will look to make amends in this competition. Check out the UEFA Europa League knockout round play-off ties in full below.

Manchester United, Barcelona, Bayer Leverkusen, Juventus, Roma, PSV, Sevilla, RB Salzburg, Monaco, UEFA Europa League, UEL Draw, Knockout Round Play-offs