5 Pivotal Factors to Decide Champions League Group E

Barcelona will begin the defense of their UEFA Champions League title in Group E, where Roma, Bayer Leverkusen and BATE Borisov lie in wait.

The Catalan side claimed their fifth European title last June by beating Juventus in the final, in the process finishing off a remarkable treble of trophies on the season.

Roma, meanwhile, finished second in Serie A, and Bayer Leverkusen took fourth in the Bundesliga. BATE Borisov, conquerers of Bayern Munich in 2012, won the Belarusian Premier League in 2014.

Here, B/R outlines five pivotal factors that could decide Group E.

Group E Fixtures

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Here is an overview of the fixtures in Group E. Home team is listed first.

Sept. 16

Bayer Leverkusen vs. BATE Borisov

Roma vs. Barcelona

Sept. 29

Barcelona vs. Leverkusen

BATE vs. Roma

Oct. 20

BATE vs. Barcelona

Leverkusen vs. Roma

Nov. 4

Barcelona vs. BATE

Roma vs. Leverkusen

Nov. 24

BATE vs. Leverkusen

Barcelona vs. Roma

Dec. 9

Leverkusen vs. Barcelona

Roma vs. BATE

How Will the Transfer Ban Affect Barcelona?

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Barcelona will be clear favorites to advance, and rightly so. The Catalans lifted the Champions League last season to complete a glorious treble, and Luis Enrique has a squad that boasts some of the world's best players.

At the top of that list stands Lionel Messi, the diminutive Argentine forward who scores goals in bunches and has the ability to make any defender on any team look foolish. Neymar and Luis Suarez round out probably the best front three on the planet, while Andres Iniesta leads the midfield and Javier Mascherano and Gerard Pique marshal the defense.

If the team has a flaw, however, it's that as of now, Enrique has exactly the same squad as last year. Barcelona are currently operating under a transfer ban, meaning no new players could join the club this summer. Barca did conclude deals to add midfielder Arda Turan and defender Aleix Vidal, and although both will be strong additions, neither can play until January.

As a result, Barcelona are more vulnerable to injuries and suspensions than they normally would be. That doesn't mean the team will be weaker for the first half of the season, only that the potential for trouble exists until reinforcements arrive.

That might not sound like much, but for Barcelona's opponents in Group E, it could represent the minor edge needed to pull off a shock.

Luis Enrique Returns to Rome

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Before he managed Barcelona to the treble, Luis Enrique led Roma for a single season, 2011-12. It was a disappointing campaign, and Enrique left the club after Roma failed to qualify for Europe.

He'll return to the Eternal City on Matchday 1 as a European champion. While both Enrique and Roma have moved on, you can be sure both will be hoping to put one over the other. If nothing else, though, the match will represent a challenge for Barcelona, as Lee Roden writes at ESPN FC:

"

After dominating title rivals Juventus in a 2-1 Serie A win on the last day of August, (Roma) have good reason to be confident they can upset stronger sides if they're on form. The addition of Edin Dzeko up front means the Italian outfit have changed significantly since these two teams last met in a summer friendly. Barcelona are still favourites but can't and won't take Roma lightly.

"

For his part, Enrique has said his time in Rome made him a "better coach." According to Football Italia, he said: 

"

It was my fourth year as a coach, after three with the youth team (at Barcelona). It was very intense and rewarding, a unique experience.

I’ll always be grateful for the opportunity they gave me, I arrived with different ideas about how to play football, and found players ready to accept that change and a crowd which was behind us.

I have great memories, I’d have liked to have finished higher (than seventh), but it was a very positive year.

"

After the best year of his managerial career, Enrique's return to Rome will give him a chance to start another campaign on a good note.

Roma's Difficult Start

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As noted in the previous slide, Roma have a good squad that is capable of upsetting top teams on a given day. But Rudi Garcia's men will face a difficult start to their Champions League campaign, and if they are to advance, they'll have to overcome it.

The good news is that Roma will open their Champions League campaign with a home game on Matchday 1. The bad news is that Barcelona, the defending champions, will be their opponents.

If Roma lose that match, they will be under pressure to take points off BATE Borisov and Bayer Leverkusen, the other two teams in the group. Complicating that task is the fact that Roma must play each of those teams away from home on Matchday 2 and 3, respectively.

Roma should have more talent than BATE, but a trip to Belarus won't be easy. The match against Bayer should be more of a toss-up, but home-field advantage will benefit the Germans.

All in all, it adds up to a schedule that could hardly be trickier for Roma.

The Race for 2nd Place

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The landscape in Group E appears clear: Barcelona are the favorites, and BATE are the long shots. Roma and Leverkusen, therefore, will probably compete head-to-head for second place.

That makes the two matches between Roma and Leverkusen potentially pivotal. The two will meet on Matchday 3 and 4, with Leverkusen hosting the first game before traveling to Italy for the return encounter.

The Bundesliga team lost forward Heung-Min Son to Tottenham Hotspur in the transfer market, but teenager Julian Brandt appears a promising prospect on the wing. Midfielders Karim Bellarabi and Hakan Calhanoglu are two more rising stars for Roger Schmidt's side, which play a high-pressing, counter-attacking style.

The team that takes more points from those two games should expect to finish second behind Barcelona.

Can BATE Stun Another Giant?

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BATE Borisov have reached the Champions League group stage four times—in 2008-09, 2011-12, 2012-13 and 2014-15. None of those previous four appearances have resulted in trips to the knockout phase, but BATE collected a famous victory against Bayern Munich (that season's eventual champions) three years ago.

Is another stunning upset in the cards? Probably not. Having become semi-regulars in the group stage, BATE are a known commodity for more teams now. And this year's squad isn't as talented as the one that beat Bayern in 2012.

The Belarusians squeaked through the qualifying rounds, scoring six goals in six games. Five different players scored, with only Aleksandar Karnitski finding the net more than once.

Anything can happen, but don't expect BATE to surprise anyone this time around.