Mia Fishel has lift off at Chelsea! USWNT star is Emma Hayes' best like-for-like Sam Kerr replacement and must be given proper chance

Although Chelsea would end up winning the cup tie, their performance was stodgy at best. For starters, they required extra-time to triumph against a team who have managed just one WSL victory all season and are averaging under a goal a game.

Viviane Asseyi opened the scoring in the first half, catching Zecira Musovic off guard with a snapshot from outside the box after the rusty Kadeisha Buchanan failed to deal with a straight ball over the top from Mackenzie Arnold. It wasn't just at the back that Hayes' side struggled, either.

Starting with Lauren James at centre-forward, with Fran Kirby just behind and Guro Reiten and Johanna Rytting Kaneryd out wide, the Blues could not get their attack clicking in the first hour. After the game, Hayes put this down to a lack of match sharpness, with Chelsea's previous game coming all the way back on December 20 against Hacken in the Champions League. "Not playing is the biggest factor. You’re rusty, you’ve got to build the combinations, the relationships," she said.

One of the only bright spots in Chelsea's clunky offensive display was Mia Fishel. Introduced in the 59th minute as a bonafide No.9, it did not take her long to make a game-changing impact. With Chelsea seemingly heading for a shocking, early FA Cup exit, she brought Rytting Kaneryd's knock down under her spell in the box before unleashing a swivelled half-volley which flew past Mackenzie Arnold and into the roof of the net.

It was a predatory strike, straight out of Kerr's playbook, and it provided Chelsea with the impetus to go on and win the game in extra-time. First, Cuthbert nodded home Rytting Kaneryd's typically pinpoint cross, before substitute Aggie Beever-Jones did what she does best, coming off the bench to score the dagger seconds before the interval.

After the game, Hayes revealed her delight at the American's contribution from the bench: "Mia Fishel came in and took her wonderful goal. That will do wonders for her."

Fishel's strike was only her second since joining from Mexican side Tigres this summer. All things considered, she's enjoyed a promising but perhaps slightly underwhelming start to life at Chelsea. The early signs were certainly encouraging, though.

In a similar script to the West Ham game, Fishel scored an important goal which helped mask a less-than-stellar performance against Tottenham on the opening day of the WSL season. Rising high to meet Niamh Charles' cross in the first half, the 22-year-old placed a perfect header into the far corner.

With Kerr ruled out of that game with injury, Fishel played the full 90 minutes and was impressive, showcasing some nifty link-up play and pressing from the front as Chelsea eventually secured a 2-1 victory. However, at full-time, Hayes was quick to point out that there was still a long way for her to go before she would be trusted as a regular starter.

"There's other steps for her to take. Her link-up and hold-up play is really good, but sometimes I want a second movement from her. Physically she still has to develop to be able to that," she said.

And these comments would prove to be prophetic. In the weeks and months that followed, Fishel has found first-team starts very hard to come by, racking up just 321 minutes in all competitions prior to the West Ham game. In some ways, this is completely understandable. When handed a start in a 6-0 victory over Aston Villa at the beginning of November, she failed to make the net bulge - something she really could have done with if she was to have any chance of seriously pushing Kerr for a spot in the starting XI.

And as a result of her being restricted to an impact role off the bench, she has struggled to find her goalscoring rhythm, something that has similarly plagued the Australian's other Chelsea understudies - such as Ramona Bachmann and Beth England - in recent years.

But that could all be set to change. With the James No.9 experiment faltering badly against West Ham, Hayes will surely be convinced to hand Fishel a place in the starting XI for the foreseeable future.

It's not how the Blues boss normally does it. Generally, new signings are introduced to the team gradually, with Hayes placing extreme importance on the squad understanding the various combinations and partnerships of her system, especially when it comes to young players.

It takes an extremely precocious talent to fast-track their way into the starting XI, with German sensation Sjoeke Nusken a rare, recent exception. Now, Fishel may also see her minutes increase. She is the closest like-for-like replacement for Kerr in the current Chelsea squad and that will not change before the end of the month, with Hayes ruling out January transfer activity in response to the injury.

"The club always have long-term recruitment plans in place and that is what we will always do. We’re never reactive," she told reporters on Sunday.

Fishel's elevation to a more senior role should not just be seen as a matter of convenience, though. There's plenty to suggest that she can help Chelsea be the best version of themselves during the second half of the season.

The issues caused by playing without a recognised centre-forward were plentiful against West Ham. First and foremost, it's a role that clearly does not get the best of James. The English phenom is at her best when she picks the ball up in enough space to drive at defenders. She knows that too, and couldn't help dropping back to collect it against the Hammers, leaving the Blues without a presence in the box.

This issue could have been alleviated if the two wide players: Reiten and Rytting Kaneryd, made runs beyond the opposition defence, but this is not their primary strength, particularly in the case of the Norwegian who led the WSL for assists last season (11). Indeed, against West Ham it was infuriating to witness the pair consistently get into promising crossing positions, only for Chelsea to be left without an aerial presence in the penalty area due to James' wandering.

Relying on Kirby, who was playing as an advanced midfielder on Sunday, to crash into the box does not get the best out of her own playmaking abilities either. And while Cuthbert is always good for a goal, considering the amount of defensive work she's tasked with, it's probably not feasible to expect her to consistently fill the scoring void left by Kerr's injury. Simply put, the combination does not work in its current form, and it's hard to envisage that changing.

It would be simplistic to conclude that starting Fishel would have solved all of Chelsea's issues on Sunday. But Hayes did seem to hint that she trusted the £250,000 ($318,000) striker to start moving forward.

"For sure, she has to. I have confidence in Mia. She needs time and she needs minutes. Up until today she’d only played 321 minutes. We need to give her a bit of time," she said.

Unfortunately, time is not a luxury Chelsea are blessed with as they prepare for an exceptionally busy month. By the time February hits, their Champions League fate will have been decided by games against Real Madrid and Paris FC, while they also host Manchester United in a crunch WSL clash at Stamford Bridge on Sunday and have to travel to Brighton on January 27.

It's a potentially season-defining run, and Fishel will likely be heavily involved as Hayes aims to avoid a repeat of her side's blunt display against West Ham. In brighter news, the forward is set to be joined by close friend Catarina Macario in the matchday squad too.

Not deemed fit enough to feature on Sunday, Hayes again assured journalists that the former USWNT regular is "not far away" from making her long-awaited Blues debut following her summer move from Lyon. Macario is another option up front - although one who will likely suffer from similar issues to James - but for now, Chelsea's attacking hopes seem to be pinned their other American star.