Salah is leaving Liverpool at the end of the season after nine years with the club.
Speaking at a charity function last week, Szoboszlai was asked about the Egyptian's announcement and told the Liverpool Echo: "Yeah, I don't have to talk too much about it because everyone knows.
"The numbers speak for themselves, the stuff he has done on the pitch speaks for itself and he is one of the best that has ever played.
"That is not only for Liverpool, I think the world as well and I am happy I was lucky to play with him and I really happy that I can say he is one of my friends."
The Hungary captain also said: "To be honest maybe you know I am very close with Mo.
"We had a lot of talks about what is going to happen in the future and it is his own decision. He is a grown man, it’s his own decision.
"He knows what to do. I think he is professional enough to act in a way that he has to because to leave with one of the trophies we are going for would be amazing.
“He is every day in training being a good example for all of us. For the new guys, the old guys, everyone. He shows us about being a better player and a better human, so he has had a big impact on his career.
"Mo is one of my best friends in the squad, he is with me all the time but Milos (Kerkez) is with me as well all the time, so we are the three. Milos is my little brother and Mo is my big brother."