Federico Pastorello spoke positively about the 28-year-old goalkeeper, who brought to an end eight years with Udinese to sign for the Nerazzurri in an €11 million deal earlier this summer.
"With Handanovic, Inter have a goalkeeper in place for 10 years," the agent was quoted as saying by Tuttomercatoweb.
"It was a choice of rejuvenation [to sign for Inter]. I think he can be considered one of the [best] two, perhaps three goalkeepers in the world.
"With him in goal, Inter have secured a top [goalkeeper] for 10 years."
Andrea Stramaccioni's side resume their Serie A campaign away to Torino next week.