Hugo Lloris is the first-choice goalkeeper at the North London outfit, while Michel Vorm is his deputy.
Gazzaniga, who worked with Pochettino at Southampton, is expected to be the third-choice custodian for Spurs and push Vorm.
Tottenham manager Pochettino has explained his decision to sign the 25-year-old Argentine goalkeeper in the summer transfer window.
“I think we need another keeper because we have Hugo Lloris and Michel Vorm,” Pochettino told Football.London when asked about Gazzaniga.
“I think we have very good keepers in the academy, like Alfie [Whiteman] and Brandon [Austin], but they are still so young. The gap with Hugo and Michel was massive.
“I think Paolo was a perfect profile for us to bring. We know him from our period at Southampton.
“He was the best keeper last season in the Championship, at Rayo Vallecano in Spain, and I think there’s no doubt about signing him and creating more competition in our goal.”
Gazzaniga is a good goalkeeper, but it is hard to see the Argentine push Lloris for a place in the starting lineup anytime soon.
The France international is one of the best goalkeepers in the world, and if he is not injured, then he is virtually guaranteed to start for Tottenham.
Vorm has been linked with a move away from Spurs in the summer transfer window, with The London Evening Standard crediting Crystal Palace with interest in the Dutchman.