Joe, who regularly captains Miguel Llera's Under-18s, will link-up with fellow Saddlers prospect Tom Leak, who is enjoying an extended stay with Steve Claridge's Whites having joined them on an initial one-month loan earlier this season.
18-year-old Willis made his first-team debut in January as the Saddlers faced Portsmouth in the EFL Trophy and will spend at least the next month with Salisbury on a 'work experience' loan.
Joe remains eligible to play in reserve matches for Brian Dutton's development side whilst also taking part in competitive first-team fixtures for Salisbury.
Willis will also be splitting his time between both Walsall and Salisbury training sessions as the club continues to keep a close eye upon his development.
Joe remains eligible to play in reserve matches for Brian Dutton's development side whilst also taking part in competitive first-team fixtures for Salisbury.
Willis will also be splitting his time between both Walsall and Salisbury training sessions as the club continues to keep a close eye upon his development.