The 23-year-old was a €15m (£12.7m) arrival from Anderlecht two years ago but has failed to make the grade in Manchester, setting up just two goals in 38 matches for the Premier League champions.
Gomez is arguably the only recognised left-back in Pep Guardiola's ranks, but Nathan Ake, Manuel Akanji and Josko Gvardiol have both been preferred in that area of the pitch in recent months.
During the 2023-24 campaign, Gomez played just 449 minutes in 15 appearances and did not start a single Premier League game, although he featured from the off twice in the Champions League.
In total, Gomez totalled a paltry 48 minutes in the 2023-24 Premier League season, and the former Borussia Dortmund and Barcelona left-back has been tipped to depart after entering the last two years of his contract.
Man City 'have buy-back and sell-on clauses' for Gomez
Despite claims that Sociedad wanted Gomez to replace Arsenal loanee Kieran Tierney, it was reported earlier this week that Serie A giants Roma had emerged as the favourites for his signature.
However, journalist Fabrizio Romano reports that Sociedad have in fact won the race to sign Gomez, who will join the La Liga giants in a deal worth an initial €9m (£7.6m).
While that price tag means that Man City are taking an initial hit on the Spaniard, Romano adds that the Premier League champions have also obtained a 15% sell-on clause and retain an option to buy him back again.
The two clubs are now set to thrash out the final details of the transfer before Gomez's signing is made official, and the defender will leave Man City with two Premier League titles, one Champions League, one Club World Cup, one FA Cup and one UEFA Super Cup.
Gomez is set to become the third player to leave Guardiola's ranks this summer, as Tommy Doyle joined Wolverhampton Wanderers in a £4.2m switch, while Taylor Harwood-Bellis's Southampton move was made permanent for £19.5m.
Which Man City players could follow Gomez out of the exit door?
Man City's summer exodus is not expected to stop with the departure of Gomez, as a handful of other young products and unwanted troops will likely be cut from the ranks in the coming weeks.
Among the chief candidates to leave are midfield outcast Kalvin Phillips, James McAtee - back from his latest loan spell at Sheffield United - and Jack Grealish, who has failed to live up to his £100m expectations.
Senior players such as Bernardo Silva and Ederson do not have their long-term futures set in stone either, while Yan Couto - back from his Girona loan - could be offered out too.
However, Gomez's sale does beg whether there could be a route back into the Citizens team for Joao Cancelo, who is useful, versatile option at the back and proved as such during his loan spell with Barcelona.
It remains to be seen whether La Blaugrana can stump up the funds for a permanent deal, but Gomez's imminent exit could see Guardiola do with an out-and-out left-back for the 2024-25 season.