With two matches gone, the group stage of this season's Champions League has started to take shape.

This week the third round of matches, which also sparks the start of the traditional double-headers, will take place and here Sports Mole has selected five things to look out for over the course of Tuesday and Wednesday night.

Gunners on the verge

When the fixtures revealed that Arsenal would face Bayern Munich on matchdays three and four, it was imperative that Arsene Wenger's side got their campaign off to a positive start. After all, having been defeated by the Bavarians in 2013 and then again in 2014, it's fair to suggest that Bayern have Arsenal's card well and truly marked.

However, defeats to Dinamo Zagreb and Olympiacos have left the North Londoners bottom of Group F and quite frankly in need of a miracle if they are to advance beyond the group stages. In contrast, the imperious Bayern have won both of their encounters by an aggregate scoreline of 8-0.

The Emirates Stadium is certainly a profitable venue for Bayern's Thomas Muller, who has scored on both of his visits. Unfortunately for the Gunners, the 26-year-old has been in great form this term, having scored 11 goals in 12 outings. Were he to score for a third game in a row, it could go a long way to sealing Arsenal's fate.

Madrid face La Decima hero

"If ever I score a goal, I will not celebrate because deep in my heart I will never forget what I experienced at Real." Those were the words of Angel di Maria, who was recently speaking to French television station Canal+.

Prior to his failed move to Manchester United in the summer of 2014, Di Maria spent four years at the Bernabeu with Real Madrid. In total, the 27-year-old made 191 appearances and scored 36 goals to help Los Blancos win the La Liga title and two Copa del Rey trophies. The headline moment, though, was his performance in the Champions League final against rivals Atletico Madrid in 2014. He may not have got his name on the scoresheet in the 4-1 win that secured La Decima, but the playmaker was named the man of the match.

Now at Paris Saint-Germain following his £45m switch from United, Di Maria has hit the ground running in the French capital. Ahead of this encounter, he has scored twice and made three assists in his six Ligue 1 outings.

Aguero-less City

Out for around a month with yet another injury, Manchester City certainly didn't miss the influence of Sergio Aguero when they took on Bournemouth at the weekend. Raheem Sterling and Wilfried Bony took over the mantle from the Argentine as the Cherries were put to the sword at the Etihad Stadium.

Yet, Sevilla, who travel to East Manchester on Wednesday, are bound to provide much sterner opposition and are highly unlikely to be in as charitable mood as Bournemouth goalkeeper Artur Boruc was. With goalscoring openings potentially at a premium, City are going to need to be clinical.

As far as the Champions League is concerned, City have relied heavily on the stricken Aguero. He scored six of their 10 goals in the competition last season - a haul which included a memorable hat-trick against Bayern. In the campaign before he found the next six times in as many outings. With a return meeting in Seville on the horizon, it's vitally important that City make the trip having claimed three points from this fixture.

Gladbach haunted by Juve trio

Having lost their first two group matches, one of the last places that Borussia Monchengladbach will have wanted to be travelling to on Tuesday night is Turin - home of Juventus. After all, the Old Lady have not been beaten in Europe at the Juventus Stadium in their last 10 outings.

Not only that, Gladbach could potentially be up against three familiar faces, although not welcome ones. When representing Wolfsburg and Bayern, Juve striker Mario Mandzukic lost just once in six games against Die Fohlen. The Croatian also found the net during Bayern's 3-1 victory in August 2013.

Holding midfielder Sami Khedira had a 100% winning record against them from his three games in a Stuttgart shirt, while ex-Wolfsburg and now Juve centre-back Andrea Barzagli also never tasted defeat when he came up against Gladbach.

Memories of 2008 for United

When Man United's Wayne Rooney and Michael Carrick, as well as assistant manager Ryan Giggs, arrive in Moscow, they will do so with fond memories of the place. That is because the trio all featured in the Russian capital in 2008 when the Red Devils beat their Premier League counterparts Chelsea on penalties to win Europe's premier club competition for a third time.

The venue will be a different one, though, with CSKA Moscow having switched from the Luzhniki Stadium to the Arena Khimki, which has a capacity of around 18,500.

The opponents will also harbour positive memories for United winger Antonio Valencia, who scored his first Champions League goal for the club when the two sides met at the same stage in October 2009. It proved to be a match-winning moment as the Ecuadorian's strike handed Sir Alex Ferguson's men all three points.