Selling Andre Onana to Man Utd was another Beppe Marotta masterstroke! Inter's new No.1 Yann Sommer is one of the signings of the season

The problem, of course, was how to replace a goalkeeper that had wowed the watching world with his daring distribution of the ball during Inter's unfortunate Champions League final loss to Manchester City last June.

With former No.1 Samir Handanovic having retired at the end of the of 2022-23 campaign, coach Simone Inzaghi was understandably getting a little antsy as the start of a new season approached with his employers still searching for an Onana successor.

However, on August 7, after protracted negotiations, Marotta and his colleagues agreed a €6m (£5.1m/$6.5m) fee with Bayern Munich for Yann Sommer, which, combined with the Onana sale, is already looking like one of the greatest tricks Marotta has ever pulled.

He has plenty of previous, of course. At Juventus, Marotta completed the construction of the 'BBC' backline - one of the finest in football history - with the acquisition of Andrea Barzagli for just €300,000 and completely altered the course of Italian football by taking Andrea Pirlo to Turin on a free transfer. Marotta also convinced Paul Pogba to leave Manchester United when his contract expired in the summer of 2012, before then sending him back to Old Trafford in 2016 for a world-record fee.

He's continued to work wonders since joining Inter. For example, selling Romelu Lukaku to Chelsea for £97.5m only to then take him back on loan a year later for just €8m really was quite the manoeuvre. And even when the Belgian betrayed Inter by reneging on an agreement to make his loan stay at San Siro permanent, Marotta went out and picked up Marcus Thuram, a free agent that has incredibly proven an even better foil for star striker Lautaro Martinez than Lukaku.

The stunningly successful Onana-Sommer swap is arguably even more impressive, though. With his fantastic range of passing, Onana had quickly become integral to the way in which Inzaghi wanted his side to build from the back. The fear was that he would be sorely missed and Sommer appeared not only an underwhelming replacement, but also little more than a short-term solution.

The Swiss may have been a painfully familiar face to Italian football fans, given Jorginho failed to convert two penalties against Sommer during the Azzurri's unsuccessful bid to qualify for the 2022 World Cup, but he was 34 at the time of his arrival and Bayern's willingness to let him leave was not viewed as a positive sign.

Sommer, though, has been sensational right from the start of the season, slotting seamlessly into Inzaghi's starting line-up and proving an integral member of the best defence in Europe right now. Only last week, he saved a late penalty against Fiorentina to secure a 1-0 win that put Inter back on top of Serie A, a point clear of Juventus having played one game fewer than the Bianconeri, whom they host on Sunday.

The clean sheet at the Artemio Franchi was, quite incredibly, Sommer's 18th in all competitions this season, which is four more than any other goalkeeper across Europe's 'Big Five' leagues - and twice as many as Onana.

Of course, he's lucky to have the likes of Francesco Acerbi and Alessandro Bastoni playing in front of him, but Sommer is always there when called upon, with the 35-year-old boasting the best save percentage (a staggering 85.19) of any goalkeeper to have played at least 10 games this season. By way of comparison, Onana's is a desperately poor 67.59 percent.

Perhaps even more impressively, though, Sommer has proven himself just as proficient in possession as his Inter predecessor. In fact, he has actually completed more passes this season (773) than Onana (759) - and just six fewer than arguably the ultimate sweeper-keeper, Ederson.

Furthermore, while Sommer is earning rave reviews from the Italian press for his performances, who have been quick to point out that he's proving a massive upgrade on Onana, Manchester United's new No.1 has become a serious cause for concern because of his constant and costly gaffes.

Consequently, former Red Devils have been lining up to slate the decision to let David de Gea go at the end of last season and replace him with the even more error-prone Onana.

"David was a goalkeeper you could rely on and Onana is not that," ex-United full-back Paul Parker told SpilXperten. "I'm wondering if Onana will ever perform well for Man United. What are his strengths, actually? I don't know.

"He is confident on the ball but he is still miles away from Ederson or Alisson, even though everyone expected him to be on that level with his feet. He is definitely struggling both mentally and physically, way more than he did in Italy."

By complete contrast, Sommer has settled quickly into his new surroundings. As a food-lover that used to blog about the diet of professional athletes, he is savouring Italian cuisine, as well as enjoying the many cultural delights of Milan.

On the field, meanwhile, he says he feels "protected and safe" because of the presence of Acerbi & Co., and completely at ease with Inzaghi's tactics. "I am a really explosive goalkeeper, so I try to be courageous, to help the team and be an option for them with my feet," he told the club's official website.

"I try to give a lot of confidence to the team, calm as a goalkeeper and be consistent. That’s a big reason I like to play for Inter. Simone Inzaghi likes to play out from the back and that's my style of goalkeeping as well."

In short, Sommer looks as comfortable at San Siro as Onana appears out of place at Old Trafford. Nobody could have predicted such a scenario at the start of the season - not even Marotta - but it's not in the least bit surprising that yet another deal has worked out wonderfully well for him.

"I can't predict the future," he recently stated after being asked about Onana even returning to San Siro one day, "but, in football, anything can happen." And particularly when the transfer market's greatest puppet master is pulling the strings.