USA No.1 Zack Steffen experienced highs, lows and everything in-between in part I of his Fortuna Düsseldorf adventure in Germany's top flight. bundesliga.com explains why part II promises more ups than downs...

Before you say anything, we know Fortuna's position in the relegation play-off spot after 17 matches is precarious to say the least - but hear us out.

The odd goal decided half of Die Flingeraner's four wins during the first half of 2019/20. They shaded the other two by a two-goal swing, and recorded three draws. Three points less, and Düsseldorf would be propping up the rest of the table, instead of being only two adrift of the safe house at halfway.

And while the 11-goal Rouwen Hennings has had a big say, it would be verging on a travesty to gloss over Steffen's role in Fortuna's survival fight.

Watch: Zack Steffen, a Bundesliga star in the ascendant

The 24-year-old made the second-highest number of Hinrunde saves (67) of all Bundesliga goalkeepers following his summer loan move from Manchester City. Only Union Berlin counterpart Rafal Gikiewicz pulled off more (69).

The difference is Steffen, as well as standing behind the division's third-most shaky defence, had tendonitis in his left knee to contend with - not just here and there, but throughout the first half of the campaign.

Despite withdrawing from the US's November CONCACAF Nations League roster, he managed to play in 18 of Fortuna's 19 Bundesliga and DFB Cup assignments.

"My first half year at Fortuna was full of ups and downs," he admitted in an interview with kicker. "The quality is a lot higher than in America, and so are the shots I have to deal with. I've had a lot more work to do, but I've enjoyed it.

"Fortunately my knee is a lot better now. The winter break has done it good."

With his knee suitably thawed out, Steffen will be playing for Fortuna's top-flight future, as much as his own, in the weeks and months ahead.

The USMNT goalkeeper is due to return to parent club Man City in the summer, but has already said how he would like to prolong his stay at Düsseldorf, on one condition.

"Extending my contract here would only be an option if we stay in the Bundesliga," Steffen told Bild in early January. "As a young goalkeeper, I need games and experience at the top level. That's what I'm getting at Fortuna. I have a good thing here."

Needless to say Fortuna coach Friedhelm Funkel would welcome a longer or even permanent tenure.

"When Zack's fit and his head is clear, no one's taking the No.1 shirt off him," the 66-year-old said, having recently welcomed back Michael Rensing, the former Bayern Munich, Cologne and Bayer Leverkusen custodian and his first-choice in 2018/19, from injury. "He also has the potential to get even better."

Watch: Zack Steffen has featured in more than one highlight reel this season

Freiburg spotted Steffen's talent in January 2015, but the Pennsylvania native struggled - by his own admission - to adapt to life in Germany and turned out just 14 times for the reserve team, before returning to the States with Columbus Crew in summer 2016.

"I thought I would go over there, and everything would be glamorous, but it was tough," he recalled of his first stint on European soil. "Now I'm five years older, I'm more mature, and I understand the soccer world a bit better. I knew from my time in Freiburg what to expect when I was coming over here.

"My sister's come over, too. It keeps the homesickness away, the loneliness. I mean, you come to a different country and you are six hours ahead of everything you know back home. The team have really helped me as well."

It's hard to belive Steffen (c.) didn't cut the mustard in his first attempt to crack the Bundesliga. - imago images/Kirchner-Media

Steffen has reciprocated in kind. He moved to Fortuna just two days after the conclusion of the 2019 CONCACAF Gold Cup, where he kept four clean sheets prior to the USA's 1-0 defeat to Mexico in the final.

The American made his first appearance for his new club in the pre-season win against Rayo Vallecano and played the full 90 minutes of Fortuna's 3-1 victory at lower-league Villingen in the DFB Cup first round, before starring on his Bundesliga debut against Werder Bremen.

Steffen was untested in the first half, but made a telling contribution after conceding the equalising goal to Johannes Eggestein early in the second period

All told, he pulled off a not insignificant 10 saves across the 90 minutes as Fortuna ran out 3-1 winners.

"When he comes charging out, with the physique he has, you definitely think twice about whether to go for the ball or to get out of the way," commented Fortuna teammate Kaan Ayhan after the game. "He's a top goalkeeper."

Watch: Relive Zack Steffen's memorable Bundesliga debut

A further 57 stops, along with a couple of clean sheets, between Matchdays 2 to 17 have only enhanced Steffen's reputation. He even saved a penalty in a 2-1 defeat to Freiburg on Matchday 6, becoming the first Fortuna keeper to repel a Bundesliga spot-kick since Georg Koch way back in 1996.

Although 36 Bundesliga goals conceded and the occasional boo-boo have blotted the Steffen copybook, Funkel does not need reminding that Fortuna would be a lot worse off without their gloved crusader.

"He's come up with some big saves for us," he acknowledged. "We're lucky to have him."

Friedhelm Funkel (l.) expects Steffen (r.) to be his first-choice goalkeeper for the duration of the American's stay at Fortuna. - imago

Steffen is living proof that Fortuna favours the brave. He didn't let his Freiburg experience sever his Bundesliga aspirations, and has tackled a bad knee head-on to realise them at Düsseldorf.

What is set to be his 18th Bundesliga appearance, when Fortuna entertain a Bremen team boasting compatriot Josh Sargent this weekend, will also mark his first without physical restraint. Back-to-back Bundesliga victories - Fortuna beat Union on Matchday 17 - would be another notch on the belt of the US No.1.

Furthermore, a positive result could go a long way to deciding the fate of a club that hasn't achieved three successive seasons of Bundesliga football for almost 30 years.

"It's not been easy, but it's a great team," Steffen told bundesliga.com prior to the winter break. "I'm enjoying it, but I can still improve - I'm working on it. We have a lot to accomplish in the new year."

Chris Mayer-Lodge