The 21-year-old has been in superb form this season and secured the PFA Young Player of the Year award on Sunday night.
Alli's rise has not gone unnoticed at some of Europe's biggest clubs and Barcelona legend Xavi fuelled speculation by reportedly suggesting Guardiola is keen to take the England international to the Etihad Stadium.
Pochettino subsequently laughed off the claim Alli could join City and Guardiola has now advised his managerial rival to remain calm about the situation.
"Mauricio Pochettino has to stay calm. Dele Alli will be his player next season. I am pretty sure about that.
"We don't want him," Guardiola to a press conference ahead of the Manchester derby.
"He is a fantastic player - good, new, English footballer. He's a fighter. He's good.
"He's someone who attacks the box and is one of the most fantastic players I have ever seen in my life.
"But Manchester City doesn't want Dele Alli," the Spaniard insisted.
Alli, like the majority of his teammates, has committed his long-term future to Spurs after signing a contract that will keep him at White Hart Lane until 2022.
City, meanwhile, are expected to invest significantly in their squad this summer with Guardiola's first season in charge destined to end without a trophy.