The Bundesliga is back – and how. The Rückrunde gets going in mouthwatering fashion when the champions, Bayern Munich, travel to face Bayer Leverkusen, one of the top flight's most forward-thinking sides, on Friday night.

The BayArena has in recent years become something of a bogey ground for Bayern, who have not won there in the Bundesliga since March 2013, when a certain Jupp Heynckes was in charge.

Two coaches and almost five years later and Heynckes is back in the Bavarians' dugout and looking to repeat that triumph, although on this occasion there's a different cast of players on both sides. Allow bundesliga.com to break down the key head-to-heads that will shape the contest.

Watch: Check out what happened when these sides met in Munich on Matchday 1!

The flying wingers: Leon Bailey vs. Arjen Robben

There is a pretender to Robben's throne. Long has the flying Dutchman paraded gleefully down Bayern's right flank, usually cutting inside onto his left foot and hammering past a helpless goalkeeper from long range, but, so far this season, Robben has been outshone by Bayer's Bailey, who has also perfected the knack of scoring eye-catching goals.

The Jamaican's goals are not just eye-catching, though, they are important, too. Two of Bailey's six goals this season have put Leverkusen ahead in games; the other four have been equalisers. Coming into this meeting with Bayern, Die Werkself are on a 12-game unbeaten run, the best in the league – it is no exaggeration to attribute a large part of that recent success to Bailey, whose scoring return is only bettered by Kevin Volland (nine goals) and assist return (four) is only bettered by Kai Havertz (five).

The 20-year-old's performances have been such that kicker rated him as the best attacking midfielder in the Bundesliga based on displays in the Hinrunde, while Bild chose him as the best player of the first half of the season. Bailey insisted to the latter publication, however, that such accolades are merely "incentives to get better".

Watch: Bailey discusses his favoured position with bundesliga.com

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It is in the hunt for improvement that Bailey could look to Robben, his opposite number on Friday night. The Dutchman enjoyed a run of nine successive games after Heynckes took over, although back and muscular problems limited his involvement towards the end of the Hinrunde.

Although that means he has found the net less than Bailey (Robben has three goals this season), the statistics indicate that Robben is in fact more influential to his side: the 33-year-old sees more of the ball than Bailey, misplaces fewer passes and – crucially – wins a far higher percentage of his one-on-one defensive duels. Robben is a better-rounded, more complete player than the Jamaican youngster at present.

Not surprisingly, Bayern have not lost any of the 14 games (W11, D3) that Robben has started this season, while he also became the Bavarians' all-time leading foreign goalscorer in the Bundesliga with his opening goal in the 3-1 Klassiker win against Borussia Dortmund on Matchday 11.

Bailey has certainly made a very promising start to his Bundesliga career, but – on his day, and even if those days are fewer and further between nowadays – Robben remains the top flight's king on the wing.

Watch: Enjoy Robben's top five Bundesliga goals!

The Chilean craftsmen: Charles Aranguiz vs. Arturo Vidal

Under the radar, Aranguiz has developed into one of Bayer Leverkusen's most effective players this season, an unsung midfielder amid an orchestra of attacking soloists. The Chilean has bounced back well after losing his place when Tayfun Korkut took over at the BayArena last March, becoming one of Heiko Herrlich's most-trusted on-field conductors.

The 28-year-old sees more of the ball than any of his team-mates (averaging 76 touches), while an average of 12.1 kilometres (7.5 miles) covered also points to his tireless effort to clean up behind whichever potent attacking quartet Bayer field.

Although he only featured in 12 games in the Hinrunde after suffering a calf injury, Aranguiz slotted right back into midfield when fit and will be tested to the limit on Friday night by his compatriot Vidal, who he once told bundesliga.com was "a warrior and someone who fights; he's a player who really adds to the team".

Watch: Aranguiz ran the show as Bayer beat Freiburg on Matchday 4!

Vidal has certainly added to Bayern this term: the 30-year-old has scored five goals, already his personal best tally in a Bayern shirt.

In typically combative style, Vidal responded to Heynckes' criticism of his performances by finding the net in four successive games between Matchdays 12 and 15, and returns to his old stomping ground (where he was managed by Heynckes) in perhaps the form of his Bundesliga life.

While Vidal's goalscoring numbers outweigh those of Aranguiz, who has found the net once this season, the statistics also indicate that the Santiago native is enjoying a better season than his La Roja teammate: handed a slightly less disciplined midfield role than Aranguiz, Vidal has fired in more shots, played more passes and won more one-on-one individual duels, supporting claims that he should be regarded as the best box-to-box midfielder in the world.

Watch: Vidal is enjoying a season to remember in Bayern colours

The brains on the flank: Julian Brandt vs. Franck Ribery

While Bailey might lead the Bayer counterattack, Brandt is no doubt the brains behind it – no player in the Leverkusen squad has laid on more shots or created more major chances than the 21-year-old, who brought up a century of Bundesliga appearances on Matchday 2, the youngest to reach the landmark in club history.

Those chances have brought two assists, while Brandt has also added goals to his game – much like his attacking teammates – perhaps the fruit of Herrlich's front-foot style: the attacking midfielder has already hit the net four times in the Bundesliga (more than the entirety of last season), in the process re-awakening longstanding interest from across the continent, including from this weekend's opponents.

Bayern will have noted Brandt's newfound consistency – he himself cited the mental side of his game as his most-improved facet as a player recently – and returns have duly improved: the Germany international has featured in every game so far this term and is increasingly being drawn into the centre from the left flank, offering plenty of scope to exercise that beguiling creative power.

Watch: Brandt joins the Bundesliga's 100 club!

It is little wonder than Bayern have cast envious eyes in Brandt's direction: fine a servant as he has been for the club, Ribery is not getting any younger, as indicated by a succession of injuries over the last few years, most recently a knee problem that kept him out for over two months between October and December.

Although he recently stated that he remains capable of magic – "It's mad how well I can play when I'm fully fit," he told Bild – the Frenchman, 35 in April, is yet to score or pick up an assist this season (although did net a hat-trick against third-tier Sonnenhof Großaspach this week) and has watched Kingsley Coman fill his vacant spot on the left flank with consummate ease.

That said, there is a kernel of truth in Ribery's comments and – as that hat-trick showed - it would be foolish to write off the Bundesliga's all-time leading assist provider (120): he is still capable of magic, and although his attacking returns have diminished, he has won more than half of his individual duels this term and sees far more of the ball than Brandt, almost always taking the correct decision with it.

The Manuel Neuer heirs apparent: Bernd Leno vs. Sven Ulreich

Bayern also apparently cast envious eyes in Leno's direction recently, and although the Bavarians' sporting director Hasan Salihamidzic denied those reports as "complete rubbish," there remains a succession issue for the champions when Neuer's contract expires in 2021 (and the FIFA World Cup winner will be 35).

A young German - 25 and already boasting 217 Bundesliga games – Leno would naturally be near the top of any Bayern shortlist, and has ticked one of the criteria already: he has proved a real thorn in the side of the Bavarians, keeping a clean sheet in three of his last four home games against the record champions.

On top of that, he is good with his feet - now a staple for a goalkeeper - and has attempted 210 long passes this season. That said, Leno's other numbers indicate room for improvement: the Bayer No1 has only been able to clear 64 per cent (a relatively low percentage) of shots on goal, and has also only saved 15 per cent of the opposition's major chances (also a relatively low percentage).

Bayern could do worse than look to their current No1 for a Neuer replacement: Ulreich was the best German goalkeeper in the first half of the season and, by contrast, was able to clear almost three-quarters of efforts on his goal. Over the season the 29-year-old has only conceded once every two hours, a remarkable figure.

On top of that, the former Stuttgart keeper has also saved two of the three penalties he has faced this season (denying Hannover's Niclas Füllkrug and VfB's Chadrac Akolo) – that's compared to Leno's none. While Ulreich's footwork leaves room for improvement as does his concentration (witness Wolfsburg's equaliser on Matchday 6), Bayern remain very fortunate to have him between the sticks.

Watch: Ulreich came to Bayern's rescue against his former club on Matchday 17!

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