Bayern Munich boast arguably the world’s best striker in Robert Lewandowski – a man who scored 53 goals in as many games for club and country in 2017 – so why exactly have they drafted in Sandro Wagner, a player they jettisoned in 2008?
bundesliga.com takes a closer look at what the hulking striker can bring to the Bavarian juggernaut…
1) Give Lewandowski a rest
Given the Poland striker's astonishing scoring record, the instinctive response to such a proposition is 'why would you want to?' Scratch beneath the surface, however, and it makes a lot of sense, as well as being something the 29-year-old himself requested earlier this term.
"This season's been really difficult for me," Lewandowski said. "I play from the start every three days for Bayern or Poland, but nobody can play for 90 minutes in every game all season. For me it would be helpful to play 15 or 20 minutes less from time to time. It would be an advantage in the decisive period of the campaign to have another option on the bench."
That was brought into sharper focus at the end of October when Lewandowski was substituted off against Leipzig on Matchday 10 after feeling a tweak in his thigh. With Thomas Müller also out injured, suddenly the Bavarians had no recognised striker in their squad for their next game against Celtic in the Champions League, forcing Jupp Heynckes to field James Rodriguez up front.
While Bayern won that game 2-1 there was nevertheless an acceptance within the club that something needed to be done. After all, Heynckes knows a thing or two about winning trophies, and it is telling that in the treble-winning 2013 campaign he was able to rotate between Mario Mandzukic, Mario Gomez and Claudio Pizarro in attack. They haven't had such options in the box since then and by signing Wagner, the foundations now look a lot firmer as the Bundesliga leaders seek to repeat that achievement in 2017/18.
Watch: Wagner struck against his new old club for Darmstadt in 2016
2) Big-game player
Having a back-up is all well and good, but only if they are actually able to produce the goods – something Wagner himself has never doubted. “In my eyes, I've been the best German attacker by a mile for a while now,” he said on the way to firing Hoffenheim to a first ever tilt at the UEFA Champions league last year.
That confidence is supported by the statistics. In 2009, Wagner scored twice in the U-21 European Championship final to help Germany lift the title with a 4-0 win over England in a team that included current Bayern stars Manuel Neuer, Mats Hummels and Jerome Boateng.
Watch: Wagner's top three Bundesliga goals
In 2015/16 he scored 14 of Darmstadt's 38 Bundesliga goals to help keep the unfancied promoted side in the top flight, even putting them 1-0 up away to Bayern on Matchday 22 of that season (a game Bayern eventually won 3-1).
Furthermore, Wagner was also on target away to Liverpool in the second leg of Hoffenheim's Champions League play-off tie at the start of the current campaign and recorded five goals for Germany in qualifying for the 2018 FIFA World Cup.
3) Viable Plan B
Those in the know are unanimous in their assessment of Wagner's qualities. "He offers us something a bit different," said Bayern sporting director Hasan Salihamidzic upon confirmation of the striker's arrival, echoing Germany coach Joachim Löw's view that, "He's got a different playing style and brings a different element into the game."
So what exactly is different about Wagner? Earlier this season Hoffenheim boss Julian Nagelsmann offered some insight: "He's got an unbelievable will to win. He's a nuisance on the pitch and that's good because he creates space for his team-mates." Standing at 1.94 metres (6'4") and weighing 92 kilograms (202 pounds) it is hardly surprising that he is a handful for defenders in a way that Lewandowski is not.
That could be very useful for Bayern as they seek to break down teams who invariably sit deep against them. Since Heynckes' return as coach in October, Bayern have tended to line-up in a 4-2-3-1 formation, but could now switch to a 4-4-2 in a move that would allow wingers to play on their natural flanks late in must-win games and pump balls into the box for the strikers.
Furthermore, as his physique makes him hard to knock off the ball he was the most-fouled player at Hoffenheim this term (26). With a number of high-calibre set-piece specialists to call upon, such as Lewandowski, David Alaba and Arjen Robben, those extra direct free-kicks around the edge of the box pay big dividends.
4) Aerial threat
All of which leads us seamlessly to the fact that Wagner is a monster in the air. His sheer physical prowess makes him difficult to mark, but the striker's movement and timing are also crucial. "He's improved his build-up play this season," commented Nagelsmann.
Indeed, Wagner has scored exactly half of his 36 Bundesliga goals with his head, and four of his six efforts in all competitions for Hoffenheim in 2017/18 so far have been headers. Compare that to Lewandowski, who has scored one header in the Bundesliga this term, equating to just seven per cent of his overall tally of 15.
An additional string to Wagner's bow is that he appears to thrive away from home. Bayern may have picked up more points on the road than anyone else in the league so far in this campaign but both Bayer Leverkusen (17) and Borussia Dortmund (16) have scored more than them (14) on foreign soil.
This term, Wagner has scored three of his four Bundesliga goals and contributed both of his assists in away matches. Over the past three seasons, 53 per cent of his goals have come while he was on the visiting team, compared to 37 per cent for Lewandowski over the same period. In a sport where marginal gains can have a big impact, anything that can give you an edge should not be overlooked.
5) Hometown boy
Wagner was born in Munich and came through the youth ranks at Bayern before being released in 2008 (the number two shirt number he will wear is in recognition of this being his second spell at the club). Even while the forward was at Hoffenheim his wife and children lived in the city.
This matters, because although Bayern are known the world over and have numerous nationalities within the squad, as a club they remain determined to stay true to their Bavarian roots. All newcomers are given German lessons in order to settle as quickly as possible and help them adopt the "Bayern way of life", as president Uli Hoeneß likes to put it.
There has always been a core of German players in the side, but following the recent departures of Philipp Lahm and Bastian Schweinsteiger, Müller has been the only senior member of the squad to come from the local area around Munich. Now he has Wagner for company. It is a symbolic notion perhaps, but a hugely significant one in maintaining Bayern's tradition and identity.