Serge Gnabry has scored 13 goals in 13 games for Germany

"North London is RED!!!" proclaimed Serge Gnabry after scoring four goals in a 7-2 rout at the Tottenham Hotspur Stadium in October.

It was not the red of Spurs' fierce rivals Arsenal, who Gnabry joined as a 16-year-old, but of Bayern Munich, where the German has turned into one of the most frightening forwards in Europe.

The performance catapulted the 24-year-old back into the consciousness of a Premier League audience that remembered a lightning quick but raw teenager who struggled to break through at the Gunners and endured a disastrous loan spell at West Brom.

Three years after leaving England, and about to face Tottenham again after helping Bayern book a place in the Champions League knockout stages with two games to spare, Gnabry is described as "fantastically important" to his country, "phenomenal" by opponents and an "extraordinary player" by one of his former bosses.

Missed potential in the Premier League

Arsenal were so convinced by Gnabry's talent they agreed to pay Stuttgart £100,000 so he could join their academy once he turned 16. Little more than a year after signing, he became the second-youngest player to appear in a Premier League game for the Gunners.

Gnabry featured 18 times in all competitions for Arsene Wenger's side during his first two seasons as a professional. But when the minutes dried up, he was sent on loan to West Brom for the 2015-16 Premier League campaign.

But he played just three times for Albion - whose manager at the time, Tony Pulis, delivered a telling assessment.

"Serge has come here to play games but he just hasn't been for me, at the moment, at that level to play the games," said Pulis.

"He's come from academy football and not played much league football. Does academy football really prepare players for league football? And we're talking about Premier League football here."

Gnabry, wanting more first-team opportunities, opted to leave Arsenal in 2016 and return home to Germany with Werder Bremen - not that Wenger was keen to let him go.

"He came back from a very bad experience at West Brom where his confidence was destroyed," said the Frenchman recently. "I tried to rebuild him because I believed in him."

Impatient, clinical and on Germany's radar

Alexander Nouri coached Gnabry at Werder Bremen

Even as Gnabry struggled for form and fitness in England, Germany boss Joachim Low was keeping an eye on a player who had represented his country at youth level.

Gnabry's Arsenal team-mates Per Mertesacker and Mesut Ozil even attempted to talk Low into taking a punt on him, with the forward making his international debut in November 2016, three months after leaving the Premier League.

"When he was at Arsenal, he was plagued by injury and all these injuries set him back," said Löw. "But even at the time, around the 2014 World Cup, he had always been in my thoughts.

"He had some very good games with Arsenal and Mertesacker and Ozil would say to me, 'Look at Gnabry, he's a fantastic player, he keeps defences very busy', so we had him in our sights for a long time."

On Gnabry's arrival in the Bundesliga three years ago, Werder Bremen boss Alexander Nouri discovered a player who was "a little bit impatient" but blessed with bags of potential.

"He was young and really highly ambitious, but sometimes too impatient," Nouri told BBC Sport.

"He was suffering a lot of injuries, so he couldn't consistently work on his physical strength. He wanted to come back as fast as possible."

When fit, though, Gnabry proved a valuable asset for Nouri's side, netting 11 times in 27 games during his one season at the club.

"He is just lightning quick and is tailor-made for big transition moments, he has a clinical finish with both feet," added the former Bundesliga midfielder.

"I remember he often practised finishing with his left foot after team sessions, he took a lot of balls and was working on his weaker foot - now he's scoring a lot of goals with it.

"It's not coming out of nothing; it's the fruits of efforts he put in a long time ago."

Learning from Robben and Ribery

Gnabry trains with Franck Ribery, who spent more than a decade at Bayern Munich

Nouri has kept in contact with Gnabry since he joined Bayern Munich in 2017 and visited the winger recently at Germany's team hotel while he was on international duty.

The former Arsenal man told Nouri he had learned from former Bayern stars Franck Ribery and Arjen Robben about "winning mentality and attitude", and how they would "always practice out of their comfort zone".

"We had a long chat, it was really impressive what he told me," said Nouri. "I figured out when I was talking to him that he was choosing an extraordinary way for his career.

"If you choose this way you need to commit to a lifestyle of how much effort you put in, you need to work and live for this way and my feeling was he totally committed to this. That's how he became an extraordinary player."

It is not just Gnabry's attacking prowess - he has scored nine goals for Bayern in 18 games this season - that has impressed Nouri.

"He is lightning quick, a clinical finisher, but he puts a lot of work now in his defence - that was something he was missing before," Nouri said.

"Now he's taking these deep runs back to his own box defending. He's capable of doing this work while on the other hand making deep runs for the offence.

"Before he wasn't able to do it because of a lack of strength physically. After a long period with no injuries, he could build up that strength - now he is a complete player.

"He just needs to prove this over a longer period to become a top international star."

Solving the Gnabry 'mystery'

Former Arsenal boss Wenger has suggested Gnabry's move to Werder Bremen was "manipulated behind the scenes" by Bayern Munich, who he joined after one season in the Bundesliga.

"We tried to extend his contract for a very long time," Wenger told Bein Sports, "He was always a very talented boy who lacked confidence in some stages, but we always thought we had a player who could achieve a lot."

Wenger may debate Gnabry's road to Bayern, but the forward's career at the Bundesliga champions - via a loan spell at Hoffenheim - has made him an important player for the German national team.

Gnabry has scored 13 goals in as many appearances for his country, with a hat-trick in a 6-1 win over Northern Ireland during his last outing for Die Mannschaft.

It led Northern Ireland boss Michael O'Neill to say Gnabry and Germany will have a big impact on next summer's European Championships.

"Gnabry's goalscoring record is phenomenal," he said. "It's a mystery to me how English clubs didn't get more out of him."

Gnabry has been praised by Tony Pulis for the way he responded to a difficult spell at West Brom

Germany boss Low added he "always had the highest possible opinion of Gnabry", praising his "prime qualities".

"Right from the start, it was obvious to me he would be a fantastically important player," he said.

"He was always one to pass the ball to. He doesn't play up front all the time, he lets himself fall back a bit and you can find him anywhere on the pitch. He's able to play in many different positions. His finishing is technically fantastic."

Now, even Pulis is convinced by his talent.

"You could knock me over with a feather - having worked with him at West Brom and seen him there to what he's done is absolutely amazing," he said after the last time Bayern met Spurs.

"When people show what they can really do and really knuckle down and become so good as he's done, it's absolutely fantastic. The kid's done fantastic."