Alonso has a contract with Ferrari until 2016, although that deal reportedly has a clause allowing him to leave the team if they fail to finish third or higher in the constructors' championship
The Italian outfit currently hold a slender advantage over fourth-placed Williams in this year's standings, and have yet to enjoy a race victory in 2014.
Two-time world champion Alonso has been continually linked with a return to the struggling McLaren team, yet team principal Mattiacci is seemingly confident that both the Spaniard and team-mate Kimi Raikkonen will be with Ferrari next season.
When asked by F1's official website whether Ferrari would stick with the same driver line-up for 2015, Mattiacci said: "Sure."
It has been another disappointing campaign for the team that holds the record for most drivers' and constructors' titles in F1 history.
However, Mattiacci, who took over as team principal from Stefano Domenicali in April, believes foundations are in place to ensure Ferrari return to the top of the sport.
"We have a very clear strategy and a very clear timeline," he added. "Like all serious managers you have to try to do the utmost to shorten this scenario.
"But Formula One is not soccer. It's not a case of changing one or two players and the coach and the next season you are winning.
"This is a very competitive environment with the most sophisticated engineering in the world and with great talents to contribute to it.
"We know that we have a lot of work to do, but we are starting from a very solid platform. I have found incredible assets in this company. We have the most talented couple of drivers, we have a tradition of over 60 years, and an impressive obsession to come back and win."