New signings can take time to settle, but others join new clubs and hit the ground sprinting like Bayern Munich's Serge Gnabry, Borussia Dortmund's Paco Alcacer and Axel Witsel, or RB Leipzig's USA international Tyler Adams.
bundesliga.com has picked out 10 new arrivals who instantly repaid the faith their clubs showed in signing them.
"When talking about our position, Serge and 'King' [Coman] are two very good youngsters," said Arjen Robben when tasked to find the men who will replace Franck Ribery and himself on Bayern's flanks, an opinion shared by former Bayern striker Claudio Pizarro. This season, both fledgling talents have shown they can live up to that big-time billing.
Watch: Analysing Serge Gnabry's game
Bayern had snapped up Gnabry in summer 2017, but his season-long loan spell at Hoffenheim made him feel like a new arrival at the start of the 2018/19 campaign. His Bundesliga pedigree, established first at Werder Bremen, has been confirmed as — with ten league goals, second only to Robert Lewandowski in the Bayern squad — he became just the third man in the German top-flight's history to reach double figures for three different clubs in three successive seasons.
Witsel's return to Europe after an 18-month spell in China was accompanied by as many question marks as his decision — aged just 27 — to go to the Far East, though not for the same reasons. The main one was: Could he still cut it at the top level? The answer: You betcha.
The Belgium international, now 30, gave the critics a spectacular response on his Bundesliga debut with an overhead kick in the 4-1 demolition of RB Leipzig on Matchday 1. Any doubting voices have long been silenced with Witsel providing the silk and steel combination so badly needed in the BVB midfield throughout the campaign.
Belfodil was another who arrived in the Bundesliga with question marks. Tagged as 'talented' since his days in the Lyon youth academy, his picturesque career path took him to Sinsheim via Italy, the UAE, Belgium and Bremen, and in the PreZero Arena, he finally — aged 27 — appears to have found a place to call home.
Four goals in the Hinrunde equalled his Bremen tally of 2017/18, but he caught fire in the Rückrunde, netting 12 times — including a first senior hat-trick in the 4-0 dismissal of Augsburg on Matchday 28 — to prove a perfect and prolific foil for Andrej Kramaric.
Paco Alcacer (Borussia Dortmund)
Robert Lewandowski can — in part — thank Lucien Favre for his fourth Torjägerkanone as the Bundesliga's leading scorer. Runner-up Alcacer finished four goals behind the Bayern man, but played seven games fewer. All of Lewandowski's appearances were starts, his BVB rival made just 11, and played the full 90 minutes only three times.
Watch: Paco Alcacer's roots
The summer arrival from Barcelona certainly made the most of his time on the pitch, surpassing Gerd Müller and Grafite as the striker with the best goals-per-minute ratio in Bundesliga history at one strike every 66 minutes. "His finishing has been on another level," noted sporting director Michael Zorc, who saw the Spain international grab a 34-minute hat-trick against Augsburg on Matchday 7, a sizeable chunk of the seven goals he plundered in his first four Bundesliga appearances to set the tone for an outrageously prolific debut season.
When you have Jovic, Kramaric, Kai Havertz and Marco Reus for company in third place on the Bundesliga's top scorers' chart on 17 strikes, you must have done something right. The summer signing from Alkmaar most definitely did as he became Wolfsburg's highest-scoring Bundesliga debutant ever.
Only 2008/09 title-winning front duo Edin Dzeko and Grafite have ever matched the 6'5" Dutch forward's feat of netting two hat-tricks in a top-flight campaign for the Wolves with his Matchday 34 triple in the demolition of Augsburg taking him well beyond his initial ambition of 12 league goals this season. Not that the Netherlands international will rest on his laurels. "I have to deliver throughout the season," explained the 26-year-old, who hopes to be part of his country's UEFA Nations League challenge this summer. "I can still improve."
With Ribery bowing out, France has lost its most iconic representative in the Bundesliga, but Mateta could help fill the gap. Like Belfodil, Mateta's potential was spotted early by Lyon, and he also failed to establish himself with the seven-time French champions. Instead, Mainz has been the place where his talent has first blossomed on the senior stage, and he has already set a new record for French players in the Bundesliga.
His return of 14 goals marks the best-ever haul for a French debutant in the German top flight, surpassing the likes of Anthony Modeste, Jean-Pierre Papin and — bien sur — Ribery. A place in France's UEFA U21 EURO squad for this summer's tournament is just desserts for Mateta, who became only the sixth Mainz player to register a top-flight hat-trick in the 5-0 win over Freiburg on Matchday 28.
When Hamburg suffered their historic first relegation last season, top-flight teams came to cherry-pick the best of their squad. Kostic joined Frankfurt on a two-year loan — he has performed so brilliantly, the Eagles have already made the deal permanent, 12 months before they had to.
An attacking midfielder for most of his career, the Serbia international has been converted by Adi Hütter into one of the Bundesliga's most adroit left wing-backs: his attacking instincts brought him six league goals and 10 assists while the work ethic he has always had served him and his side well in their own final third. "Filip has been a real stroke of luck for us," said the club's sporting director Fredi Bobic, who initially brought Kostic to Germany by signing him for Stuttgart from Groningen in 2014. "His dynamism, determination and flexibility have played a major role in the positive way the season has panned out.
Could Leipzig's January addition from New York Red Bulls be the Bundesliga's best US import yet? Christian Pulisic and Schalke's Weston McKennie have paved the way, and Adams has raced across the Atlantic to catch up with them, immediately looking at home in Die Rotenbullen's midfield.
But for injury, he would have made more than the nine impressive league appearances he got under his belt, and also potentially improved on the rock-solid statistics he put up, including two laser-guided assists for Yussuf Poulsen goals. "I think he’s exceeded my expectations, our expectations," Leipzig assistant coach Jesse Marsch said. "There’s been some talk, like I’ve done so much to help Tyler, adapt and do well here. I don’t think it’s hurt, but Tyler is the reason Tyler has been successful."
After a disappointing time at Everton, Klaassen arrived in Bremen with a reputation to repair. Come the end of the 2018/19 campaign, he had polished it up very nicely indeed.
The ex-Ajax midfielder was the glue holding together the Green-Whites' ultimately unsuccessful charge for a top-seven finish, featuring in all but one of their league games and contributing a handy five goals and four assists to the cause. "We'll start next season on a higher level than we were last summer," said Klaassen, whose own arrival is a major reason behind that.
Kevin Trapp (Eintracht Frankfurt)
Trapp spent three fine years at Frankfurt prior to his 2015 switch to Paris Saint-Germain, so when he found himself behind newly crowned FIFA World Cup winner Alphonse Areola and the legendary Gianluigi Buffon in the French capital, a return to Germany's financial hub was an obvious choice.
It has been a beneficial comeback for both parties: Trapp has refound confidence and playing time, and in making the second-most saves of any Bundesliga goalkeeper last season, helped take the Eagles into next season's Europa League after backstopping their 2018/19 run to the semi-finals.