The Champions League returns this week with a number of intriguing round of 16 ties set to get under way.

Liverpool, who won the competition back in 2019, are in action along with last season's runners-up Paris St Germain.

Here, the PA news agency takes a look at some of the talking points before the first legs begin.

Chance for Liverpool to channel focus?

Jurgen Klopp conceded defeat in the Reds' Premier League title defence on Saturday and the Champions League is their only other opportunity to finish the season with silverware. The draw was not kind, pitting them against RB Leipzig, but the tournament represents a chance for the 2019 winners to regain a purpose. If they can produce a strong display in Budapest – with German Government coronavirus regulations not allowing Klopp's side to travel to the country – it could provide the lift they need to keep fighting until the end.

Another opportunity for Nagelsmann to catch the eye

On the other side of the coin, RB Leipzig and their highly-rated manager Julian Nagelsmann will view this week's first-leg tie as another chance to make a mark. After they reached the last four of the Champions League last August, the once-dubbed 'Baby Mourinho' will be out to show it was no flash in the pan. The 33-year-old has various suitors and more success over an English club, after they essentially knocked out Manchester United back in December, will do his growing CV no harm.

Neymar-less PSG visit Barca

Former Real Madrid team-mates and current international colleagues Pepe and Cristiano Ronaldo will do battle at the Estadio do Dragao on Wednesday as Juventus visit Porto. Together the pair won the competition on multiple occasions during their time at the Bernabeu and Juventus striker Ronaldo will be desperate to add a sixth European crown to his record. While good friends off the pitch, this week's clash will no doubt be a fierce contest given their hunger to win.

Sevilla out to improve Champions League record

While Sevilla are Europa League specialists, the elite European competition has proved more tricky for them to crack. Only once in the last six decades have they made it to the quarter-finals but they have a great opportunity this year. In superb form over the last two months and up against an inconsistent Borussia Dortmund side, Julen Lopetegui will aim to continue to rebuild his career after a chastening spell at Real Madrid.