Roma president James Pallotta says there is "no chance" the club will sell Alisson at the end of the season.
The 25-year-old goalkeeper has been one of the stars of Roma's season and has been linked with clubs including Real Madrid and Champions League semi-final opponents Liverpool.
The Brazil international still has three years left on his contract, though, and Pallotta has no desire to cash in on a player who cost just €8 million in July 2016.
"We have no intention of selling him. No chance," he told Sky Sport Italia.
"When we signed him, I thought he was a great goalkeeper and I still think so, so we won't sell him."
Roma were held to a 0-0 draw in the derby by 10-man Lazio on Sunday, leaving them fourth in the Serie A table, just a point ahead of Inter.
The race for the Champions League spots means they cannot relax their league commitments in order to focus on the semi-final clash with Liverpool, the first leg of which takes place on April 24.
Pallotta, though, is already thinking of the prospect of reaching the final, having watched his side produce a stirring comeback to knock out Barcelona on away goals in the last eight.
"Why shouldn't we think about the final? Liverpool are a strong team but we can play well, too," he said.
"We did well in Barcelona and the score did not reflect what we saw on the pitch in the first leg. We took them by surprise in the second, thanks to the coach."