Serge Gnabry emitted immense confidence ahead of the World Cup after completing what he believes was a transformation from "so-so player" to the brilliant attacker he is today.

Gnabry was not in Germany's squad for the last World Cup, despite breaking into the side two years earlier.

At the time of Russia 2018, the talented attacking midfielder had just completed a spell on loan at Hoffenheim from Bayern Munich, but he would soon become a key player for both Die Roten and the national team.

Germany became the third successive defending champions to be eliminated at the World Cup group stage four years ago, ushering in a period of transition that undoubtedly benefited Gnabry.

But Gnabry did not always look to be on a path to such stardom. He failed to live up to early expectations at Arsenal and endured an underwhelming loan spell at West Brom, where manager Tony Pulis surmised the youngster was not good enough to play regularly.

Gnabry is unsure how he turned his fortunes around so significantly, but there is no doubt about his confidence as Germany prepare to open their Qatar 2022 campaign against Japan on Wednesday.

"I don't know, at some point, I managed to flip the switch from being a so-so player to becoming the Serge Gnabry that I want to be," he told reporters at Germany's training base on Sunday.

"It's always difficult to really pinpoint what the reasons were. Even if there's a bit of a low, you keep working hard and maybe, as a player, you really give too much time and thought on why you haven't scored this, why you haven't done that.

"But really, when called upon [we need] to delete these negative thoughts, to delete any negativity from our heads and, of course, play well.

"Making good assists and scoring lots of goals in the Bundesliga for Bayern, that has certainly helped and that helps us to approach the coming challenges with a great deal of self-confidence.

"So, I'm absolutely looking forward to the coming games and I hope that I can give my all, just as I have recently in the league."

Gnabry's form backs up his confidence, as the 27-year-old has already had a hand in 19 goals (10 scored, nine assisted) in all competitions this season, a haul only six other players across Europe's top five leagues can better.