The second-tier tournament may be derided by some but it offers the 18-year-old his best chance of proving himself worthy of more regular game time at Stamford Bridge.
One wouldn't bet against him. After all, Ampadu has already been making headlines at international level.
But then, that has long been obvious to anyone who has been tracking the development of a player that broke into Exeter's Under-18 side at just 14.
He was still only a boy, yet to take his school exams, when he lined out for the senior squad, too, aged 15 years, 10 months and 26 years old – making him the youngest player in the club's history.
Ampadu was promptly snapped up by Chelsea, where he quickly came to the attention of former manager Antonio Conte, who knew right away that the Blues had a prodigiously gifted talent on their hands.
Ampadu was fast-tracked into the first team, handed his debut in an EFL Cup clash with Nottingham Forest 12 months ago. Six more first-team appearances followed and he became the second-youngest player to play in the Premier League for Chelsea when he came off the bench against Huddersfield Town in December of last year.
Conte's exit during the summer may have looked like bad news for Ampadu but new boss Maurizio Sarri utilised him a lot in pre-season.
The former Napoli coach Sarri has yet to pick him in the Premier League but he has been very vocal in his admiration of Ampadu and it was telling that the youngster was included in the Italian's Europa League squad, unlike £35 million midfielder Danny Drinkwater.
Indeed, if, as expected, Sarri makes wholesale changes to the side that defeated Cardiff 4-1 at the weekend, Ampadu is likely to start in midfield on Thursday, especially as Ruben Loftus-Cheek is set to miss the game in Greece after picking up an injury on international duty.
Ampadu has also previously been employed in defence but Exeter's former Director of Football Steve Perryman believes that the hometown hero has always been destined to play in the middle of the park, arguing that the teenager is an all-round talent.
"In a midfield three, sometimes you have one who just defends, one who just gets forward and one who does a bit of both," Perryman told Goal. "My opinion is that Ethan would be one who does a bit of both.
"When he is playing against players who are a lot older, like he has always done so far, I think he is better coming onto the ball and playing in defence. He can play in a three or a two and he will be better in that position until he gets older.
"But I have the confidence that he can handle it [at Chelsea] as a midfielder. His big advantage is that he makes good decisions. Pass it left or right, dribble? He will always make the best call."
Ampadu is obviously still developing, so he needs regular game time to hone his skills. Both Neil Warnock of Cardiff City and Frank Lampard at Derby County have recently admitted to trying to take Chelsea's next big thing on loan for the season.
The Blues refused and although that will prompt concerns that he could go the way of many other academy products by spending more time on the bench than on the pitch during his key, formative years, everyone at Stamford Bridge believes that Ampadu is capable of becoming a first-team regular.
"Ethan has shown great potential and unbelievable maturity since arriving at Chelsea a year ago," club director Marina Granovskaia enthused after the player had penned a new five-year contract on Wednesday.
"In this short time he convinced a lot of people with his exceptional quality and mentality and we look forward to watching him develop into a key player for the club over the coming years."
Chelsea have a history of discarding world-class talent, such as Mohamed Salah, Kevin De Bruyne and Romelu Lukaku. However, the contract extension is clear proof that the Blues will not make the same mistake with Ampadu.
They know they have a potential world-beater on their hands. The Europa League offers Ampadu a welcome opportunity to prove it.