With the reputation of being a utility man, Gundogan has transformed himself into an accomplished attacking threat this term, regularly providing game-changing contributions for Pep Guardiola's men.
It was not meant to be this way.
And Man City didn't need to spend, although the solution they found was not the one they had expected.
That’s no slight on Foden either. The 20-year-old has simply been tasked with a different role in a different position as he is far less akin to David Silva - one of Man City's greatest ever players - in style than many would have you believe.
But while Foden is thriving on the left-hand side, it is Gundogan who has been tasked with providing the tempo and rhythm from the centre of the pitch - pivotal parts of Man City’s play that were so evidently lacking from the league leaders' game in the opening weeks of the season.
The Germany international has often been deployed as a holding midfielder during his time at the Etihad Stadium. Guardiola clearly trusts the 30-year-old, and he has been brought out in the bigger games to add some solidity to the Cityzens engine room throughout the Spaniard's reign.
At the start of the current campaign, though, the 2018 champions' midfield needed support even against the unlikeliest of opposition, such was City's struggles. Gundogan was routinely the man tasked with providing that stability, as shown with the position he takes up in the picture below.
As you can see, Gundogan - the player illustrated by the arrow - is hanging back from a Man City attack where seven of his team-mates are further advanced than him. While this may not be too unusual, it is indicative of the expectations placed upon the former Borussia Dortmund man at the start of the season.
Guardiola was preferring to play a 4-2-3-1, that morphed into 4-2-2-2 with Kevin De Bruyne pushing up alongside the striker, over his preferred 4-3-3 formation. This was largely due to the loss of Silva and the fact that Rodri appeared incapable of providing the same defensive cover as Fernandinho did in City's title-winning campaigns under the ex-Barcelona manager.
But after the drab 0-0 draw with local rivals Manchester United in December, Guardiola started to become more adventurous and attacking with his tactics once again, and the transformative role of Gundogan was crucial to this change of approach.
The above image shows Gundogan - again illustrated by the arrow - taking up a perfect position near the penalty spot, waiting for a Raheem Sterling cut back at home against West Brom after joining a City attack. He swept the ball home into the far corner to score his first league goal of the season, just three days after the stalemate at Old Trafford.
The image below is against the same opposition, although at the Hawthorns this time, and depicts Gundogan bursting beyond the Baggies' defence to bring down a perfectly weighted Joao Cancelo pass. This passage of play had the same outcome as the German took a touch, got the ball out from under his feet and buried it in the bottom corner.
Neither of these two instances would have been possible prior to the United game. Gundogan has bagged seven Premier League goals in his last eight outings - the most he had ever scored in an entire season before this recent run was six.
Nevertheless, he is bringing far more than just goals to the team. In City's games at the start of 2020/21, they were missing a conductor, someone who knows when to slow the game down or speed it up, and also has the ability to do just that against top-level opposition. Silva used to be the man for the job and although Foden has many excellent qualities, being able to exert that level of control over proceedings is not one - not yet anyway.
And that's where Gundogan has come in. His ability to adapt to every new role Guardiola throws at him has seen him become a jack of all trades and a master of most.
When comparing where Silva received all of his passes in his last campaign with City to where Gundogan has in 2020/21, the similarities are there for all to see.
Over the last few weeks, we've become accustomed to seeing Gundogan in a more advanced midfield role, predominantly taking up residence in the left half space that Silva called home for a decade.
Though, it's not just Silva's positioning that Gundogan has managed to almost perfectly replicate. He's also producing stats that are almost identical to those of the Spanish World Cup winner.
As the above graphic indicates, City's No.8 uses the ball in a remarkably David Silva-esque way - much more so than Foden, who plays fewer passes, has far fewer touches of the ball and prioritises using his exceptional and incisive dribbling skills to hurt the opposition rather than doing so by becoming the City conductor. This is further depicted in the chart below.
So Guardiola was right, City had no need to dip their rather large toe into the transfer market last summer, but it was perhaps for reasons even he had not predicted.
Being coined a utility man is never usually a label dished out laden with praise, but having the ability to morph yourself into a world-class operator all over the pitch brings a whole different meaning to the phrase.
Gundogan flourished in the Fernandinho role, has excelled in the Silva position and may now be forced to try his hand in the post that De Bruyne is likely to vacate for several weeks following a hamstring injury. If anyone is capable of doing it, then it's Gundogan.