And, according to Pretorius, the opportunity to be part of the journey is something he couldn't turn down.
He said: "Dean and Carl have ambitions to take Worcester to the top of the table and I've got the same ambitions.
"When they put that to me and told me it was a case of focusing on the long-term, I decided it was something I want to be part of."
The Welsh international has already experienced life under Dean Ryan and Carl Hogg during his academy days with Gloucester.
And Pretorius admits the pull of the duo was a significant factor in his decision to move to Sixways.
He continued: "Having worked with them before it means I understand what they expect from players.
"I value the ethos they have towards the game so of course they had a big part to play in my decision to move to Warriors."
Pretorius captained the Cardiff Blues side during the last campaign and went on to make his debut for Wales last summer.
But the 28-year-old admits he is looking forward to making Sixways his new home when he joins in the summer.
He added: "I know that Sixways is a great place with an incredible fanbase. They're very loyal fans and that makes it even more of an exciting challenge."