The stage is set: Manchester City will take on Barcelona and Arsenal will face reigning champions Bayern Munich in the UEFA Champions League round of 16. Chelsea will host former star Didier Drogba and Galatasaray in a reunion manager Jose Mourinho said he was relishing while Manchester United look to have a clear path through after they were paired against Greek side Olympiakos.

There are few easy draws at this stage of Europe's grandest tournament -- but some are harder than others. When Arsenal relinquished its lead in Group F to Borussia Dortmund in the final round of play in the Champions League group stage last week, they nearly got bounced out altogether by Napoli , only avoiding outright disaster on goal difference. Still, manager Arsene Wenger understood that they were at the mercy of the first knockout round draw.

The first legs will be played on February 18-19 (Image: FABRICE COFFRINI/AFP/Getty Images).

But Monday morning's draw in Nyon, Switzerland at UEFA's plush headquarters showed them no such clemency. Rather, it coupled them with defending champions and still-improving world-beaters Bayern in a home-and-away series that will kick off on FOX Sports 1 and FOX Sports 2 on Feb. 18.

After years of tortuous and torturous decline, Arsenal put things back together early on this season. Rejuvenated by the acquisition of playmaker Mesut Ozil -- incomprehensibly made available by Real Madrid -- the spring returned to their steps and the zip to their passing. But they only just survived a brutal group stage draw, losing to Napoli 2-0 where a third goal would have eliminated the Gunners. For their immense troubles, their reward is a rematch with the best team of the tournament.

Painfully for Arsenal, this very matchup reprises the rotten pairing they received at this stage last year, when Bayern dashed out of London with a 3-1 first-leg win, signaling their title candidacy. Arsenal's 2-0 win in Bavaria saved their face, but not their campaign, with away goals doing them in.

Since the arrival of Josep Guardiola, who jammed as much silverware into Barca's trophy case as it could physically hold, Bayern, unthinkably, have grown even stronger. While wingers Franck Ribery and Arjen Robben continue to run rampant, the machinery surrounding them has kicked up a gear or two.

Manchester City are, of course, one of the sport's nouveaux riches, buttressed by Emirati oil money. In their two prior forays into Europe in the seasons previous, they crashed out of admittedly very tough groups. They were given a more forgiving assignment this time around and sailed past Viktoria Plzen and CSKA Moscow. On the final day, they even overcome a 2-0 deficit at Bayern to pull out the 3-2 win , the Germans' only blip in the season to date -- whether domestic or continental.

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But in Barcelona they meet a challenge of a different magnitude. The Catalans have suffered through meandering form in recent months, as star forward Lionel Messi has battled injury and fitness. But they have nevertheless won this tournament three times in the last seven years and typically blossom in the spring.

Chelsea's prodigal son returned, flamboyant manager Jose Mourinho, had announced ahead of the draw that he'd quite like for his Blues to be paired with Galatasaray in the next round. The Turks have invested heavily lately, bringing in Drogba among others. The tough as nails Ivorian rose to prominence under Mourinho at Chelsea and was the man who willed and muscle them to the Champions League title in 2012 with a team largely built by the Portuguese. Mourinho had hoped for this homecoming, a chance, perhaps, to pay tribute to the man who says he thinks of his old coach as a father.

In the other matchups, Greek juggernauts but European minnows Olympiakos got Manchester United, likely spelling doom for the former and a reprieve for United's embattled manager David Moyes. United have not lost a Champions League game against Greek opposition, winning seven and drawing one. That streak should continue, particularly if star Robin van Persie can get back to full health. While few think the Red Devils have the weapons to win this tournament -- including Moyes, who ruled out such a thing earlier this year -- failing to advance off this draw would be a disaster.

AC Milan , which reached this stage by the skin of their teeth -- scrapping to a 0-0 draw at home against Ajax , which saw them through on the last day -- will quite possibly be handed their European ending by Atletico Madrid , whose season has been far more fruitful.

Bayer Leverkusen , Germany's current number two, were paired with that other moneybags side, Qatari-funded Paris Saint-Germain . This contest, too, is hard to call ahead of time even if, on paper, PSG has the superior players.

Schalke 04 are capable of the occasional European run, but aren't likely to start one over Real Madrid. If the Spaniards haven't won this tournament in 11 long years, they remain its kings, with 10 titles, and their vast reserves of talent aren't likely to allow them to stumble this early on.

Finally, Zenit Saint Petersburg were drawn with Dortmund, last year's runners-up and the darlings of the game's more aesthetically-inclined fans. The Russians may be a considerable hurdle for Die Borussen, but one they ought to be able to negotiate if they are to make it back to this year's final, to be held May 24 in Lisbon.