19-year-old, Stoke-on-Trent born Slinn, will spend the entire 2018/19 campaign on loan to local Evo-Stik Southern League Premier Central side Rushall Olympic as Keates seeks to secure some much-needed first-team football for his latest summer signing.
Speaking via the club's official website - Saddlers.co.uk - Dean said; "I had my eye on him at Wrexham and he is someone who I have monitored ever since. Getting him out on loan straightaway suits all parties because it means he can gain some valuable experience.
"He will be in most days with us, despite being on loan, meaning he will be in and around the squad and learning off Dunn and Robbo. He’s got a competitive game at the weekend, which is great for him, and we know Rushall will look after him."