Alisson has established himself as one of Europe's top keepers this season, excelling in Roma's run to the last eight of the Champions League and reportedly attracting interest from Liverpool and Real Madrid.
But Pallotta is confident that the 25-year-old Brazil international will remain in Rome, with his contract not up for another three years amid talk he could be set for an improved deal.
"Why should he leave?" Pallotta asked ahead of the Champions League quarter-final second leg at home to Barcelona. "He will stay - he has a contract.
"I love him and I have never wanted to sell him. I thought he was great and now he's showing how good he is."
Roma trail 4-1 after the first leg at Camp Nou, but Pallotta believes his side are not yet out of the tie.
"I thought the guys played well in the first leg and we got unlucky with some of the goals," he said. "If we go up 1-0, it changes it right away."