Manolas has been heavily linked with a move away from the Stadio Olimpico during recent transfer windows, with Premier League trio Manchester United, Arsenal and Chelsea all frequently credited with an interest in his services.
The highly-regarded Greek centre-back was expected to join Zenit Saint Petersburg last month after a £30m fee was agreed between the two clubs.
He looked set to put pen to paper on a five-year deal with the Russian outfit, only for it to subsequently emerge that he had not shown up for a scheduled medical. Chelsea were said to have been monitoring the situation closely at that time.
With such a transfer seemingly now dead in the water, Manolas' representative, Ioannis Evangelopoulos, has confirmed that his client has joined his Roma teammates for the start of pre-season training.
When asked if Inter Milan could renew their pursuit of the 26-year-old, he appeared to claim that Serie A rivals Juventus held an interest along with Barcelona and Real.
"Inter could be an interesting option, the same as Barcelona, Real Madrid and Juventus are," he told Tuttomercatoweb, as relayed by Sport. "There are many teams that have spoken to us."
Evangelopoulos did not elaborate on why the switch to Zenit failed to materialise. Reports in June suggested that Manolas wanted his rumoured £3.5m-per-year wages to be paid in euros, rather than roubles. Roberto Mancini has since returned to the Giallorossi to complete the signing of Argentine midfielder Leandro Paredes.
Roma will presumably be at pains to lose Manolas, having already seen defensive colleague Antonio Rudiger depart for Chelsea over the weekend. They also saw Mohamed Salah leave for Liverpool, but high-profile transfer guru "Monchi" has been busy securing permanent deals for the likes of Juan Jesus, Federico Fazio, Hector Moreno, Bruno Peres, Lorenzo Pellegrini, Maxime Gonalons and Rick Karsdorp.
Dutch midfielder Kevin Strootman recently took to social media to express hope that Rudiger's move to Stamford Bridge would be Roma's "last goodbye" of the summer.