(CNN) Cristiano Ronaldo will return to former club Manchester United with new side Juventus in the Champions League group stages.
If Juve is to win the Champions League for the first time since 1996, the Serie A side will need to emerge from a group that also includes Spanish club Valencia and Swiss team Young Boys of Bern.
United has made an uncertain start to the season in the English Premier League -- Jose Mourinho's side has lost two of the three games it's played -- and last season was knocked out by Sevilla in the Champions League last-16 round.
Holders Real Madrid will face Roma, CSKA Moscow and Viktoria Plzeň in Group G.
Ronaldo, who first won the European Cup with United in 2008, helped Real Madrid lift the most coveted trophy in club football four times in the past five years.
But his departure from the Spanish side, along with manager Zinedine Zidane, means this year's competition is one of the toughest to call in recent seasons.
"Each year is more difficult, but we will try and hopefully we can repeat," said Real midfielder Luka Modric, who was named as the UEFA Men's Player of the Year for the 2017/2018 season at the draw in Monaco, when he was asked if the Madrid team could win a fourth successive title.
Last season's beaten finalist Liverpool was handed a tough draw in Group C, which includes Paris Saint-Germain, Napoli and Red Star Belgrade.
"I am looking forward to watching PSG a bit more often, which is a very interesting project for sure over in France with Thomas Tuchel," Liverpool manager Jürgen Klopp told the club's website, referring to the French club's new coach.
"Facing Neymar will be, for our Brazilian guys, like meeting a friend again and all that stuff. It's a big challenge, but for all the others it is a big challenge to face us," added Klopp, whose Liverpool squad contains three Brazilians -- Alisson, Fabinho and Firmino.
At the star-studded ceremony in Monaco were a number of leading players, including Liverpool star Mo Salah and Real defender Sergio Ramos. Salah went off injured in Liverpool's 3-1 defeat by Real in the 2018 final following a challenge from the Spanish international.
Salah was a contender for the overall award won by Modric -- the Croat also won the UEFA award for the best midfielder of last season -- while Ramos was named best defender with Real's Keylor Navas taking the best goalkeeper prize as the Spanish team swept the board for the individual accolades.
Group B also looks a tough section as Barcelona, Tottenham Hotspur, PSV Eindhoven and Inter Milan were drawn together.
English Premier League champions Manchester City will face Shakhtar Donetsk, Lyon and Hoffenheim in Group F.
The first group stage games will take place on September 18, with the eventual champion crowned at Madrid's Wanda Metropolitano on June 1.
Last season prize money of $1.5 billion was distributed between participating clubs -- from the qualifying rounds to the final -- while winners Real walked away with over $100 million.
Champions League group stage draw:
Group A: Atletico Madrid, Borussia Dortmund, Monaco, Club Brugge
Group B: Barcelona, Tottenham, PSV Eindhoven, Inter Milan
Group C: PSG, Napoli, Liverpool, Red Star Belgrade
Group D: Lokomotiv Moscow, Porto, Schalke, Galatasararay
Group E: Bayern Munich, Benfica, Ajax, AEK Athens
Group F: Manchester City, Shakhtar Donetsk, Lyon, Hoffenheim
Group G: Real Madrid, Roma, CSKA Moscow, Viktoria Plzeň
Group H: Juventus, Manchester United, Valencia, Young Boys