Castano disclosed that he came into contact with Salisu when he set up African Talent Football Academy (ATAFA) in 2017 at Nsawam, a town in south Ghana.
He explained that he was angry with the attitude exhibited by Mohammed Salisu, because he was late for his first training and he also came without football boots.
"I remember my first time meeting him – he came without his boots and was late. I was very, very angry and I was close to telling him to go home," Castano, speaking to Stats Perform News, recalled.
"He took some boots from the goalkeeper and after 10 minutes playing, we saw something different. I talked to him and told him that if he can be serious and work, I promised him in half-year I could send him to Spain."
Salisu joined Real Valladolid in 2017 with ATFA receiving a little amount which was undisclosed from the deal, but with the expectation of earning addition money from his onward transfer.
In his debut La Liga season in 2019/2020, Salisu has been one of the best performers, making 27 appearances.
Mohammed Salisu was rated the U-21 defender with most clearances in the top five European leagues in the course of the season.
The Ghanaian defender's sensational form has attracted offers from several clubs including Real Madrid, Barcelona, Atletico Madrid, Manchester United and a host of other Premier League clubs.