The UEFA Champions League returns to our screens on Tuesday with Newcastle making their long-awaited return to the competition in one of the games of the round.

Eddie Howe's Magpies take on AC Milan at San Siro before treble winners and current holders Manchester City get their campaign underway later in the evening.

Catalan giants Barcelona are looking to make up for poor performances in Europe's flagship competition in recent years, having not won the competition since 2015, and are another of the continent's behemoths in action.

Here's what you need to know about Tuesday's Champions League fixtures.

Milan vs Newcastle - Group F

• Location: Milan, Italy
• Stadium: San Siro
• Date: Tuesday 19 September
• Kick-off Time: 17:45 BST / 12:45 ET / 09:45 PT
• Referee: José María Sánchez (ESP)
• VAR: Alejandro Hernández (ESP)

It's been 20 years since Newcastle's last continental venture and the Magpies embark on a gauntlet of a group in the final months of 2023.

Their campaign begins in Milan's footballing cathedral on Tuesday evening, with Eddie Howe's side securing a crucial win in the Premier League against Brentford ahead of this bout.

The Rossoneri, meanwhile, were once again thumped by their Milan rivals in the Derby della Madonnina on Saturday as Inter blitzed their way to a 5-1 rout. Stefano Pioli's side were semi-finalists in this competition last season and had started the Serie A season brightly before the derby thrashing tamed their mood.

Young Boys vs RB Leipzig - Group G

• Location: Bern, Switzerland
• Stadium: Stadion Wankdorf
• Date: Tuesday 19 September
• Kick-off Time: 17:45 BST / 12:45 ET / 09:45 PT
• Referee: Enea Jorgji (ALB)
• VAR: Marco Guida (ITA)

Marco Rose's RB Leizpig have started 2023/24 like a house on fire.

The tone was set just before the campaign got underway as they destroyed Bayern in the DFL-Supercup and they've since scored 13 goals in their opening four Bundesliga outings. Xavi Simons and Benjamin Sesko are poised for breakout European campaigns and this is an important fixture for the German side given Manchester City are set to dominate Group G.

A win in Bern will stand Rose's side in good stead, although Young Boys do have some pedigree in this competition and are often tough to beat on their own patch.

Feyenoord vs Celtic - Group E

Celtic are back in the big time and they've been drawn into an evenly-contested group that all four teams will fancy progressing from.

There's no simple task for the Scots in Group E and their opening fixture in Rotterdam will be tough. De Kuip is a raucous environment on nights like these, although the Dutch champions haven't had it all their own way at the start of 2023/24.

Nevertheless, Arne Slot's dynamic outfit certainly know where the goal is and Celtic must ensure they aren't overwhelmed by Dutch hostility on Tuesday night.

• Location: Rotterdam, Netherlands
• Stadium: De Kuip
• Date: Tuesday 19 September
• Kick-off Time: 20:00 BST / 15:00 ET / 12:00 PT
• Referee: Irfan Peljto (BIH)
• VAR: Ivan Bebek (CRO)

Lazio vs Atletico Madrid - Group E

• Location: Rome, Italy
• Stadium: Stadio Olimpico
• Date: Tuesday 19 September
• Kick-off Time: 20:00 BST / 15:00 ET / 12:00 PT
• Referee: Slavko Vinčić (SVN)
• VAR: Nejc Kajtazovič (SVN)

These are perhaps the two favourites to advance from Group E, although both sides head into their duel having endured disappointing defeats at the weekend.

Atletico's momentum was sapped by Valencia as they put three past Diego Simeone's side, while Lazio were second best in Turin as Juventus beat them 3-1.

Maurizio Sarri has struggled to establish himself in Europe's premier club competition, while El Cholo needs to oversee a much-improved continental campaign after last season's woeful showing.

PSG vs Borussia Dortmund - Group F

• Location: Paris, France
• Stadium: Parc des Princes
• Date: Tuesday 19 September
• Kick-off Time: 20:00 BST / 15:00 ET / 12:00 PT
• Referee: Jesús Gil Manzano (ESP)
• VAR: Juan Martínez Munuera (ESP)

The 'Group of F' is undoubtedly the most intriguing of the bunch and PSG's clash with Borussia Dortmund is set to be the most watchable of the Tuesday night Champions League fixtures.

Life under Luis Enrique had started with some promise for PSG before they were cast aside by Nice on Friday night, while Dortmund might be gaining some momentum after an unconvincing start to the season. Edin Terzic's side roared back in the second half at Freiburg on Saturday to secure a 4-2 triumph.

The German side will be out for delayed revenge after Les Parisiens dumped them out of the competition in heartbreaking fashion three years ago.

Man City vs Red Star Belgrade - Group G

• Location: Manchester, England
• Stadium: Etihad Stadium
• Date: Saturday 16 September
• Kick-off Time: 20:00 BST / 15:00 ET / 12:00 PT
• Referee: João Pinheiro (POR)
• VAR: Tiago Martins (POR)

The treble-winners are the overwhelming favourites to claim back-to-back European crowns and they've been aided by yet another kind group stage draw. Man City begin their defence at the Etihad to Serbian outfit Red Star Belgrade.

The Cityzens look to have done an excellent job of replacing those who exited the club in the summer, with Jeremy Doku adding a fearsome new dimension to Pep Guardiola's attack. Erling Haaland, meanwhile, will be looking to get his European campaign up and running with a goal or five on Tuesday night.

Red Star will look to stay in the game for as long as possible, but City have been irresistible at the start of 2023/24.

Shakhtar Donetsk vs Porto - Group H

• Location: Hamburg, Germany
• Stadium: Volksparkstadion
• Date: Tuesday 19 September
• Kick-off Time: 20:00 BST / 15:00 ET / 12:00 PT
• Referee: Davide Massa (ITA)
• VAR: Aleandro Di Paolo (ITA)

The situation in Ukraine means Shakhtar will once again be playing their home games in this season's competition away from Donetsk. The Volksparkstadion in Hamburg, Germany will play host to their Group H opener.

The Ukrainian outfit continued to lose players in the summer window and a new-look side will be hoping to make strides in this competition. They've certainly got a chance of progressing and Tuesday's game could prove significant.

With Barcelona expected to top the group despite their recent European struggles, these two sides look set to battle it out for second place. Porto, like Shakhtar, have a wealth of experience in this competition and were quarter-finalists in 2020/21.

Barcelona vs Royal Antwerp - Group H

• Location: Barcelona, Spain
• Stadium: Olímpico de Montjuïc
• Date: Tuesday 19 September
• Kick-off Time: 20:00 BST / 15:00 ET / 12:00 PT
• Referee: Radu Petrescu (ROU)
• VAR: Cătălin Popa (ROU)

After enduring back-to-back group stage exits, surely this is the year Barcelona enjoy a deep Champions League run. They couldn't have been dealt a simpler group, although nothing is ever plain-sailing for Xavi's Blaugrana in Europe.

Barca dazzled in La Liga on Saturday as their summer arrivals purred in the 5-0 beatdown of Real Betis.

Champions League debutants Royal Antwerp will be the next to feel their wrath when they visit Catalonia on Tuesday night.

READ 90MIN'S FULL MATCH PREVIEWS HERE

This article was originally published on 90min as Champions League fixtures today - your guide to Tuesday's games.