"We have a team and we are in the Premier League, and we are now in year two," the Portuguese manager told Wolves' website. "In year two we know the challenge is even more difficult, but we have something that we hold on to - we have our own identity.
"We need to bring in players and we will do so, but it is very difficult to find the right ones, because the quality that we have already is high."
First team coaches Rui Pedro Silva, Rui Barbosa, Antonio Dias, Joao Lapa and Julio Figueroa have also signed contract extensions while Ian Cathro joined as a coach on a three-year deal last month.
Santo has bolstered his squad with six recruits in the current transfer window, including Portugal goalkeeper Rui Patricio, Mexican striker Raul Jimenez and defender Willy Boly.
"The way we did it last year was absolutely amazing - I cannot thank the supporters enough. But at the same time I humbly ask, let's do it again. Together we are stronger," Santo added.
Wolves begin their pre-season fixtures against Swiss club FC Basel later on Tuesday.
(Reporting by Anirban Paul in Bengaluru; Editing by David Goodman)
