The Colombian believes the defender will be a massive boost for the young players at the club when he joins in the summer but warns Nerazzurri fans to be patient with the side
The 32-year-old has agreed a deal to join the Nerazzurri on a free transfer in the summer, and Guarin believes the Manchester United captain's experience will prove invaluable as the club looks to continue its redevelopment.
"He's an important signal for the start of the new president's project: a champion with years of experience as captain of Manchester United," he told Tuttosport.
"He's a player who will do well on and off the field. His presence will also be essential for all the youngsters who have come this year and will come in future.
"Vidic was just the man this Inter needed."
Guarin came close to joining Juventus in January before the swap deal involving Mirko Vucinic collapsed at the last minute, but the Colombia international claims the transfer debacle has helped to motivate him to become a success with Inter as they look to return to the elite of European football.
"What happened in January was a watershed: there was a before and after. What has happened has given me a lot of motivation, and also a lot of responsibility," he said.
"I knew a lot of people didn't want me to go to Juventus, but I did not expect such a strong campaign. This is the first time in my career something like this has happened.
"[Coach Walter Mazzarri] always had faith in me, he knows how I work, what I can give on and off the field. For my part, I have confidence in his work, I believe in him and what he does.
"Inter is no longer the team that won everything. We are rebuilding with quality players but we need a little patience.
"We are doing things well, on the pitch and as a club as a whole. There will come a moment when you start to see the results of this work, but now we need a little patience from everyone, especially the fans."