Inter Milan, to the surprise of everyone, crashed out of the Champions League at the group stage last season.
The eventual Serie A winners finished bottom behind Real Madrid, Borussia Monchengladbach and Shakhtar Donetsk.
But it is a new-look Nerazzurri team this time around.
Simone Inzaghi has stepped in to fill the void left by Antonio Conte as manager, Edin Dzeko has replaced Romelu Lukaku, and Denzel Dumfries was selected as the man to take over from Achraf Hakimi at right wing-back.
Real Madrid are also a team in transition. Los Blancos lost Sergio Ramos and Raphael Varane this summer and failed in a late bid to sign Kylian Mbappe.
New manager Carlo Ancelotti did manage to bring in David Alaba and Eduardo Camavinga as reinforcements, though, so the 13-times winners will be looking to improve on their run to the semi-final last time out.
Shakhtar romped to a 4-2 aggregate win over Genk in the third qualifying round before edging Monaco 3-2 on aggregate in a play-off to secure their place in the competition.
The Ukrainian side have strengthened this summer, adding attackers Pedrinho from Benfica and Lassina Traore from Ajax.
They are aiming to escape the group stage for the first time since the 2017-18 season.
Sheriff Tiraspol are making their debut in this round of the competition, having defied the odds to pick up wins over Red Star Belgrade and Dinamo Zagreb.
They are the first ever Moldovan side to play in the group stage of the Champions League.
Champions League Group D fixtures
Check back throughout the group stage for the latest results and match reports
Wednesday September 15
Sheriff 2-0 Shakhtar
Tuesday September 28
Tuesday October 19
Inter Milan vs Sheriff
Shakhtar vs Real Madrid
Wednesday November 3
Real Madrid vs Shakhtar
Sheriff vs Inter Milan
Wednesday November 24
Inter Milan vs Shakhtar
Sheriff vs Real Madrid
Tuesday December 7
Real Madrid vs Inter Milan
Shakhtar vs Sheriff
Key fixture: Real Madrid vs Inter Milan
On paper, these two teams should progress from this group — but it is not always that straightforward.
Travelling to face Shakhtar is never easy and Sheriff are an unknown quantity at this level, so points could be dropped against both.
After all, surprise results are a common occurrence in the Champions League.
Inter travel to the Spanish capital on Matchday 6 and will not want to be in a situation where they need to win in order to extend their journey in Europe’s elite club competition.
That game could, however, decide who tops the group.
One to watch: Joaquin Correa
Joaquin Correa thrived under Inzaghi while at Lazio and is already hitting his stride in Milan — netting twice on his Inter debut, in their 3-1 win over Hellas Verona.
The 27-year-old’s arrival went somewhat under the radar after Dzeko's move following the loss of Lukaku.
As well as the Bosnian No9, Inter signed someone who can rival Lautaro Martinez for a start, and having two players of that ilk can only be a positive.
Despite a greater focus being placed elsewhere, the Argentine could be one of the surprise stars of the group.
Breakout star: Eduardo Camavinga
Linked with Paris Saint-Germain and Manchester United for large periods of the transfer window, it came as something of a shock to see the French wonderkid sign for Real Madrid on deadline day.
It is unlikely that he starts regularly in the short term but Ancelotti may be tempted to give Luka Modric a breather once the games are coming thick and fast — and Camavinga can replace the legendary midfielder.
He has the potential to turn those moments into something more, and the Champions League could be the perfect stage for the 18-year-old prospect.
Experience and quality should be enough to see Real Madrid and Inter progress out of the group and into the knockout stages.
Despite a fairly quiet window, Ancelotti still has Karim Benzema, Eden Hazard, Gareth Bale and Vinicius Junior at his disposal.
Inter, on the other hand, still have the core group of their title-winning team.
They have also started the Serie A season in fine form, scoring seven goals across two matches.
Experience should help Shakhtar to third place, with the group stage being a step too far for Moldovan upstarts Sheriff.
All information correct as of 10am, September 6, 2021