English clubs are swiftly back into Champions League action again this week, with their third matches of the group stage taking place.

On Tuesday, Liverpool are at Atalanta while Manchester City host Olympiacos, and on Wednesday Manchester United face Istanbul Basaksehir away before Chelsea take on Rennes at Stamford Bridge.

Here, the PA news agency takes a closer look at the opposition clubs.

Coaches

Atalanta: After a brief spell as Inter Milan boss in 2011, Gian Piero Gasperini managed Palermo and then Genoa before becoming Atalanta coach in 2016. He subsequently guided them into the Champions League in 2019 with a third-placed Serie A finish and their debut campaign saw them reach the last 16.

Olympiacos: Former Portugal international Pedro Martins took charge of a club outside his homeland for the first time when he was appointed as Olympiacos coach in 2018. Under him the Greek outfit won a domestic double last season and got to the last 16 of the Europa League – eliminating Arsenal in the last 32, then losing to Wolves – following a Champions League group-stage exit.

Istanbul Basaksehir: Okan Buruk became manager of Basaksehir in the summer of 2019 and in the season that followed led them to their first ever league title. The former Turkey midfielder finished his playing career with the club, having spent much of it with Galatasaray and also had a spell with Inter.

Rennes: Julien Stephan was part of Rennes' coaching staff before stepping up to replace Sabri Lamouchi as boss in December 2018. They won the Coupe de France that season and third place in Ligue 1 last term has taken them into this, their first ever Champions League campaign.

European pedigree

Atalanta: The Italian club reached the Cup Winners' Cup semi-finals in 1987-88 and the UEFA Cup quarter-finals in 1990-91. That was their last continental campaign until they played in the Europa League in 2017-18, before making their Champions League bow two years later.

Olympiacos: The best performance by Olympiacos in Europe was reaching the quarter-finals of this competition in 1998-99, where they were knocked out by Juventus.

Istanbul Basaksehir: The club made their European debut in 2015-16 in the Europa League qualifying rounds and got to the last 16 of the competition last term. This is their first season appearing in the Champions League group stage.

Rennes: Rennes' Champions League bow this term comes after Europa League campaigns in each of the last two seasons – getting to the last 16 in 2018-19 was their best run in the competition.

Form

Atalanta: Gasperini's men opened their Group D matches with a 4-0 thrashing of Midtjylland in Denmark before drawing 2-2 at home against Ajax, which leaves them second in the pool. They are fourth in Serie A after four wins and two losses.

Olympiacos: Olympiacos are third in Group C after beating Marseille 1-0 at home then losing 2-0 at Porto, and second in the Greek top flight with 13 points from five games.

Istanbul Basaksehir: So far in Group H, Basaksehir have suffered two 2-0 defeats, at RB Leipzig and then at home to Paris St Germain. In the Turkish Super Lig they are seventh, having made a slow start before winning each of their last three games.

Rennes: Rennes' Group E matches to date have been a 1-1 home draw with Krasnodar and 1-0 loss at Sevilla. They are third in Ligue 1 having lost only one of nine fixtures and won five of them.

Previous meetings

Each of the four fixtures will be a first meeting between the clubs involved.