4 storylines to follow in round of 16

The stage is set for the next phase of the Champions League following Monday's draw in Nyon, Switzerland.

There will be some mouthwatering matchups, with Paris Saint-Germain and Real Madrid highlighting the round of 16, and Chelsea and Barcelona set to revive a rivalry that's been dormant for five years.

Here are the top storylines that emerged from the round of 16 draw:

Chelsea, Barcelona to reignite fiery rivalry

Barcelona's reward for winning its group-stage match is a date with a familiar foe, as the Catalan side will get reacquainted with Chelsea in the round of 16.

The rivalry between the clubs goes back almost 20 years, when the Premier League side first qualified for the Champions League in 1999. But it was their clash in 2009 that had Chelsea players fuming after a series of penalty shouts were ignored by match official Tom Henning Ovrebo, who was confronted by an irate Didier Drogba. "It's a f---ing disgrace," the Ivorian yelled, and was subsequently banned for three matches.

Yet, perhaps the most memorable moment occurred in the last meeting, five years ago, when Fernando Torres' dramatic winner helped secure Chelsea's place in the Champions League final and triggered an outburst from match commentator Gary Neville.

The two-leg encounter will also mark a return to the Camp Nou for Spanish internationals Cesc Fabregas and Pedro.

PSG can't catch a break in round of 16

Paris Saint-Germain will face yet another epic test when Unai Emery's men take on defending Champions League titleholder Real Madrid a year after Barcelona's stunning come-from-behind victory in the round of 16.

Despite the difficult draw, headlined by Neymar and Cristiano Ronaldo, officials from the French side have been positive as the club attempts to atone for last season's collapse.

"The team will be ready," Emery said, according to Jonathan Johnson of ESPN FC. "We will show how great this team is and that we are at the level of those who can win the Champions League."

There's no doubt, though, that PSG would have preferred an easier matchup in the first phase of the knockout rounds considering the team's insatiable hunger to win the Champions League.

Aside from the high-profile bout, speculation over Neymar's future is likely to dominate headlines in the buildup to the first leg in February following reports linking the Brazilian with a future transfer to Real Madrid.

Doesn't get much easier for Manchester City

The bookies' favourite to win the Champions League was handed one of the most forgiving draws of the round of 16, as Manchester City was paired with FC Basel.

On the heels of City's derby victory over Manchester United, its streak of good luck continued Monday, as the Premier League side managed to avoid difficult pairings with Bayern Munich, Juventus, Sevilla, FC Porto, and Real Madrid.

Manager Pep Guardiola won't let his side overlook the challenge that awaits it in Switzerland, especially after last season's matchup with AS Monaco, fuelled by the emergence of teenage prodigy Kylian Mbappe, resulted in the defending Ligue 1 champion upsetting City over two legs.

Uncharted territory

Three of the five English teams that progressed to the round of 16 face the difficult challenge of conquering the unknown.

Manchester City, Manchester United, and Tottenham will be pitted against teams that they've never encountered in a competitive match, with clashes against FC Basel, Sevilla, and Juventus, respectively, awaiting the Premier League clubs.

Tottenham has arguably the most difficult matchup of the five English teams in the knockout phase, while Manchester United will be tasked with getting past a Sevilla side that bowed out of the Champions League last term after a narrow loss to Leicester City.

(Photos courtesy: Getty Images)