However, it became a question of first-team opportunities. According to Cengiz's agent, Omer Uzun, City were "working in collaboration with Freiburg" with a view to signing the attacker and immediately loaning him to the German side.
Cengiz wasn't keen and instead opted to join Roma, with Monchi proving the "decisive factor", according to Omer.
Roma's sporting director had forged a reputation as one of the greatest talent scouts in world football by turning several low-cost signings into superstars during his time at Sevilla and he convinced Cengiz that there would be far less obstacles placed between him and the senior squad at the Stadio Olimpico than the Etihad.
The Spaniard proved true to his word. Cengiz started Roma's Serie A opener, against Atalanta, on the bench, but he featured as a substitute during the following weekend's meeting with Inter at San Siro before earning his first start at home to Verona on matchday three.
Cengiz clearly hadn't settled, though, either at Roma or in Rome, and his difficulties in acclimatising manifested themselves in poor performances.
He had never lived alone before and he also struggled with the language. Unsurprisingly, he found the first few months "difficult".
Before the winter break, there were even reports that the €14.9 million signing would be loaned to Sassuolo in exchange for Matteo Politano, a Roma academy graduate who had also previously worked with coach Eusebio Di Francesco at MAPEI Stadium.
This was unknown territory for Cengiz, whose career had progressed seamlessly and rapidly up until that point.
After starring in Turkey's second tier for Altinordu as a 17-year-old, he then took the Super Lig by storm with Istanbul Basaksehir, racking up nine goals and seven assists to force his way into the national team squad.
By November of last year, he had netted three times in six appearances for his country, so coach Mircea Lucescu took a vested interest in the prodigy's situation.
He spoke Italian with him to help him improve his linguistic skills and urged him to remain at Roma and resist all loan offers.
“I also advised Di Francesco to persist with him and work patiently with him because his qualities would’ve come out in the long run," the Turkey boss revealed.
"I'll be counting on him a lot in the future. Cengiz will become a pillar of the new national team."
The Roma boss didn't need convincing of the player's, though. He wasn't about to give up on Cengiz just yet.
Aside from the youngster's pace, excellent dribbling skills and powerful left foot - all of which combined to earn him the nickname 'The Turkish Dybala' - Di Francesco was impressed by Cengiz's humility and work ethic.
“Cengiz was a wise choice by the club, he needs to improve his choices, but since he arrived, he plays far more for the team than the individual," the former Sassuolo coach enthused.
“Cengiz is only 20, he came to Serie A from another world in football terms. We are not accustomed in Italy to waiting for young talent to develop and I say that with irritation.
"People are so quick to point the finger and claim he’s not good enough even to play for the Primavera youth team. You must wait for players to develop.
“Obviously a player like Cengiz needs a little more time to assimilate the change in league, the directives or movements that are asked of him.
"At this moment, the player has this capacity, sharpness and exuberance to transform what I ask for into something remarkable. I hope he can continue like this, but he must never give up or lose his humility.
“But if he keeps training with this determination and hunger, he can become a leader on the pitch.”
As a result, he continued to make use of the 20-year-old as a substitute in December before starting him on the left wing against Sampdoria on January 24.
Roma were beaten 1-0 in Genoa - their sixth game in a row without a win - but Cengiz had impressed.
His reward was a start on his preferred right wing for Roma's next outing, at Verona, and he took just 43 seconds to vindicate Di Francesco's faith in him, cutting inside past two players before finding the bottom corner with a sweet strike of his favoured left foot.
It kickstarted not only Cengiz's career but also Roma's season. They beat Benevento 5-2 the following weekend at the Stadio Olimpico before triumphing 2-0 at Udinese on Saturday. Cengiz was involved in four of those goals, scoring three and creating another.
Six months after Mohamed Salah's departure for Liverpool, it was quickly claimed that Roma had finally found a worthy successor and there was a clamour for Cengiz to retain his place in the starting line-up for the Champions League last-16 first-leg clash with Shakhtar Donetsk.
The winger had not been afforded a single minute during Roma's group-stage campaign but now Di Francesco felt the youngster was ready.
"He is in the optimal psychological mindset and can make the most of any situation," he enthused, "whereas a few weeks ago he was short on confidence and was hitting [shots] into the stands."
His remarkable transformation was underlined by the way in which he kept his composure to put Roma ahead in Kharkiv to mark his first Champions League appearance with his first Champions League goal.
The Giallorossi ultimately fell to a 2-1 defeat but, ahead of this weekend's crucial Serie A clash with a resurgent AC Milan, there is now no doubt that Cengiz will start at the Stadio Olimpico.
Manchester City or Roma? It's taken a while but Cengiz now knows that he made the right choice.