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.

Barca guide to UCL group stages

BARCELONA

History: Four-times winners, having featured in seven finals. Coming to the end of a glorious era with three triumphs between 2006 and 2011.
2012/13: Took La Liga by storm by winning it by record margin, despite former boss Tito Vilanova’s demoralising battle with cancer. Had a nightmarish Champions League as they were humiliated 7-0 by Bayern Munich in a remarkably one-sided semi-final.
Status: Faded greats needing to reassert themselves, potential to be hamstrung by over-dependence on Messi and defensive frailties.
Coach: Gerardo Martino is a legend in Argentina, with Newell’s Old Boys, but a relative unknown in Europe.
Main Man: Lionel Messi, who else? The side struggled without him at times in last year’s competition.

CHAMPIONS LEAGUE GROUP 

AC Milan 
They have won the most number of aEuropean Championship. Having coming third after a bad start in the previous season, They have to beat PSV Eindhoven to get a place in the group stages .
Managed by Massimiliano Allegri, who hasn't always had it easy since taking the reigns in 2010, the Rossoneri have plenty of artillery with the likes of Mario Balotelli, Stephan El Shaarawy and Ricardo Montolivo.

Ajax Amsterdam 
Ajax finished seven points ahead of PSV Eindhoven last season to secure their third straight Eredivise title. They have some very good players if they can hold them till the end of transfers, but challenging Barcelona may be too much for them.

Celtic 
Celtic strolled to the Scottish Premier League title last season. Their Champions League run was impressive too, qualifying ahead of Benfica in a group that included Barcelona, before succumbing to Juventus in the knockout stages.
The Hoops made a lot of friends during last season's Champions League, and manager Neil Lennon is already to looking forward to continuing some of their new friendships: 

Prediction: Winner (group), Runners-up

Bayern Guide to champions League

BAYERN MUNICH 

History : Five-times European champions, bettered only by Real Madrid and Milan. They have lost as many finals as they have won.
2012/13: German and European Champions. Bested Borussia Dortmund to the domestic title and demonstrated their class against the same opposition in the Wembley final to end 12 years of pain.
Status: Favourites to win it all. Last year’s exceptional squad, with addition of Pep Guardiola, Gotze and Thiago Alcantara, could, in principle, refine recent achievements.

Coach: Replacing Jupp Heynckes , Pep Guardiola must feel the pressure of previous season triumphs but Pep has a starry resume of his own winning it all and many times with Barcelona.

Captain: A star performer for club and country, Philipp Lahm has shown himself to be one of—if not the—finest full-back of his generation.

 CL group 

CSKA Moscow
If the current Russian champions have any hopes of qualifying for the next round, they will be hoping to take at least something from Bayern when they travel to Moscow.
Seydou Doumbia, the Ivorian forward, is a tricky striker who's likely to lead the line forCSKA, while adequate support from goalscoring winger Ahmed Musa and Alan Dzagoev, the highly coveted Russian playmaker, should give Guardiola plenty to think about when this unknown quantity come up against his defending champions.

Manchester City 
A side that should appear a little easier to grasp is English Premier League side Manchester City, who entered the group in the third pot, but will undoubtedly pose the greatest threat to Bayern's hopes of winning the group.
Yet the side that completely capitulated to fellow Bundesliga side Borussia Dortmund in last season's tournament seems to be long gone, as new coach Manuel Pellegrinihas arrived along with a host of new stars.
FC Viktoria Plzen 
The final side in Group D are Czech Republic champions Viktoria Plzen who join this company of clubs as something of a minnow. Yet despite the odds that will be firmly stacked against them, Viktoria will be able to attack each game with a whimsical lack of pressure and truly throw everything they have at each game.

 Prediction: Winners

Milan held to 1-1 draw against PSV

Milan were held to 1-1 draw against PSV in their CL qualifier as the Dutch side , coming into the encounter with five competitive games under their belts—all of which they won and any preseason doubts about how they'd fair without top-scorer Dries Mertens, now of Napoli, and with Phillip Cocu on the bench were quickly dispelled as they showed why they are termed as scout's paradise.

Milan had history with PSV and the Philips Stadion, too. In 2005, the Rossoneri lost there, but they progressed thanks to a win at home, and in 2006 they were bested by the Dutch side in the group phase of the competition.
The Eredivisie runners-up haven't featured in the Champions League group stages since 2009, but they have pedigree, including 12 appearances between 1997 and 2008. In that context, coming away with a 1-1 draw might be seen as a positive. Stephan El Shaarawy's early header means that Milan have the away-goal advantage, even though they'll be disappointed to have drawn the game thanks to Tim Matavž's exploitation of a Christian Abbiati error. PSV were the more impressive side on the night against Milan, even with El Shaarawy's goal.
The home side had twice as many shots on target, and were missing star-man Zakaria Bakkali, a 17-year-old who's scored four goals already this season. Assuming he's fit, they'll be a better side in Milan and more dangerous for having learned from their mistakes in the first leg. PSV hammered Napoli 3-0 in Eindhoven and then won 3-1 in Naples in last season's Europa League.
Since Silvio Berlusconi vowed to tighten the purse strings at Milanello a couple of seasons ago, the focus has been on youth development and long-term planning. With PSV, the benefits of such an approach are easy to see.
They've sold Mertens toNapoli, the influential midfielder Kevin Strootman to Roma, and Mark van Bommel' has retired. Yet they still look solid. The seven-times winners not only see elite European competition as the least to be expected of a club of their stature, the tournament now has a financial imperative. Milan are desperate not only to balance the books, but also to invest money into the squad, something that will be nigh on impossible without the big cheque from UEFA. From a footballing standpoint, losing out to the Dutch would have disastrous consequences for Milan and for Max Allegri.
Berlusconi isn't the coach's biggest fan, and though the pair now have something of an entente cordiale, there are few who believe the peace would withstand failure to qualify. Progression will get Allegri's side off to the right start. Failure will almost surely result in the manager losing his job and the side being thrown into turmoil.
A new manager will be hard to find and he'll have little to spend. It should be too early to even think this, but Milan's season hangs in the balance.