Big matchups of UCL group stages

Mouth Watering Clashes of Champions league group stages 

Arsenal vs. Borussia Dortmund 

Arsenal fans were in for a disappointment as they were placed in "Group of Death" to deal with BVB, Napoli and Marseille.
 It's a tough group in general and Dortmund will be the favorites to win Group F, but Arsenal could give them a great run and even take it in the end. The Gunners have looked good early in the season, and with their style, they can get on the counter and snatch a goal very quickly.

The issue will be whether or not Arsenal will be able to handle Dortmund's attack, which has brilliantly coped with departure of Mario Gotze. Robert Lewandowski and Marco Reus are still there, and Pierre-Emerick Aubameyang has wasted little time in bedding into Dortmund. Both teams play a very attractive brand of football, so this one will be entertaining for the neutrals. 

Real Madrid vs. Juventus 

The winner of Group B will almost certainly be either Real Madrid or Juventus.
There's a combined 11 European titles between Madrid and Juventus—nine and two, respectively. There's also Carlo Ancelotti facing off against Juve, a club he's no stranger to from his time as manager from 1999-2001 and subsequent tenure at AC Milan.
Just thinking about the battle in midfield is enough to make your mouth water. With Madrid, you've got Sami Khedira, Xabi Alonso, Luka Modric, Mesut Ozil and Isco. Juventus feature Paul Pogba, Claudio Marchisio, Andrea Pirlo and Arturo Vidal.
Cristiano Ronaldo could prove the difference, as the reigning Italian champions lack an attacker who can change a game like Ronaldo can. Juve have gotten better with the additions of Fernando Llorente and Carlos Tevez, though, and they're much more prepared for a deep European run.

BVB looking better without Gotze

After the Champions League defeat things at Borussia Dortmund were rather looking dull.
Mario Gotze's release clause had been activated while Robert Lewandowski was widely expected to follow suit. To make matters even worse, Bayern their Bundesliga rival were the team they were joining which were in the process of finalising a historic treble-winning campaign by defeating Stuttgart in the Pokal final.
It looked as though Bayern were slating themselves in for another dominant, uncontested season, but Dortmund general manager Hans-Joachim Watzke finally snapped, deciding enough was enough.
"Lewy" was denied the move to Bavaria he so desperately sought, and the club reinvested Gotze's transfer fee to replenish the attacking options in the side.
The best teams change to stay on top, and BVB were no different in realising this. Pierre-Emerick Aubameyang arrived from St. Etienne in France, while Henrikh Mkhitaryan was acquired from under Liverpool's noses from Shakhtar Donetsk.

Mkhitaryan is one of the most dynamic, expansive and unpredictable No. 10s in the world, and despite some bad form early on, injuries can be blamed in stifling his game.  He's the type of player who has to be sharp and fit to play well, and we're still a few weeks away from seeing the best of him.
Aubameyang offers something completely different again, and being used on the right-hand side of a 4-2-3-1 formation unlocks his ridiculous acceleration and top-end speed. While Robert Lewandowski leads the line and occupies the centre-back's attention, Aubameyang can drop off into space, receive the ball and sprint forward. Defensive lines, on the turn, hate nothing more, and when the Gabon international finds a slither of composure, he's going to be a lethal weapon in Klopp's system.
Opposite him resides Marco Reus—the player Aubameyang can aspire to become. Reus is lightning quick, too, but his close control and decision-making process are years ahead of his new colleague's.
With Ilkay Gundogan's playmaking ability, in addition to the presence of Jakub Blaszczykowski and Kevin Grosskreutz, ensures the club will have depth across the forward line.
Historically, Klopp has been fond of changing his tactics on a game-by-game basis, and he frequently moves the "playmaker tag" from player to player in order to ensure his key players aren't marked out of the game. You'll be hard-pressed to find another squad so capable of playing in so many different ways, and Klopp will feel he has an option for every potential situation he could come across this season.
Gotze may have left, but Klopp has bought so cleverly that it's arguable the club is now better off. The truth is, Borussia Dortmund are now an irresistible, varied and overwhelming attacking force, and it's looking incredibly likely they can take Bayern all the way, both domestically and in Europe.
They've started the season with nine points from nine, but it's clear the new players are still adapting—the overwhelming statistic drawn from their 1-0 win over Werder Bremen on Friday night was that 32 shots were taken on goal, yet only one found the back of the net. It's been the story of the season so far, and die Schwarzgelben have been haunted by it over the last three weeks.
But once this side clicks into gear, there will be few defences in world football capable of stopping them in their tracks.

BVB defeated Bremen 1-0

Champions League finalists Borussia Dortmund signalled their intent of making Bayern work for the Bundesliga title as they made it nine points out of nine this season by beating Werder Bremen 1-0 which does not show the true picture of BVB dominance at Signal Iduna Park.
Robert Lewandowski netted the only goal of the game after Marco Reus fed a superb ball across the box for an easy tap-in. But, in all honesty, this could have been five or six goals to nil.

Profligacy was the home side's worst enemy once again, with Pierre-Emerick Aubameyang, Jakub Blaszczykowski, Henrikh Mkhitaryan and Nuri Sahin all missing great chances throughout the 90 minutes.
Werder rarely threatened, and Marko Arnautovic's drilled effort wide of the goal just before half time was one of the only chances of note. Jonas Hoffman saw the pitch once again and looked extremely bright.

STATS

Shots: Dortmund 32-7 Werder Bremen
Passing: Dortmund 78%-68% Werder Bremen
Possession: Dortmund 60%-40% Werder Bremen