The right wing-back has impressed on loan at Borussia Dortmund for the last two seasons and had been expected to either remain at the Bundesliga club or return to Santiago Bernabeu to compete for a place in Zinedine Zidane's first-team.
However Inter have swooped for the Moroccan, with a €45 million (£40m/$50m) deal expected to be completed to Antonio Conte's team in the coming days.
The deal has widely been viewed as a surprise, however former Inter player Kharja says his old club have been interested in the player for a long time, and had previously sought his opinion on whether to sign the attacking full back.
Speaking to Italian journalist Gianluca Di Marzio, Kharja said: "[Inter director Piero] Ausilio has been following him for a long time. Two and a half years ago, when he was still at Real Madrid and was not playing, he started asking me about him several times. Inter is a major club, and Conte's tactics will be perfect for him.
"He is very strong, in all the years of the national team I have never seen anyone like him. He is very intelligent, he will be able to adapt to Italian football. He may struggle in the defensive phase, perhaps at the beginning, but he will certainly be helped. After all, even Maicon had some difficulties, then he won the treble. Hakimi is ready and will improve.
"Playing in a stadium like San Siro will be an extra stimulus: he's not afraid of anything, like me. He played in Madrid and Dortmund, also winning a Champions League. The Meazza can only charge him up."
Despite being nominally a defender, Hakimi was one of the deadliest attacking forces in Lucien Favre's Dortmund side this season, and could be deployed as a right midfielder in Conte's system at Inter.
Hakimi scored nine goals and provided 10 assists in 45 competitive games for Dortmund in the 2019-20 season.
The German club's campaign ended on a downer on Saturday, as they suffered a humiliating 4-0 home defeat to Hoffenheim in the final game of the Bundesliga season.