The former AC Milan and Napoli manager ends his short reign with Valencia languishing in 14th in the table, only one point above the relegation zone. The 45-year-old's final match was a 1-0 away defeat to Real Valladolid on Sunday. Voro takes control of first-team duties, his eighth caretaker spell in charge at Valencia.
Walton has made nine appearances for Barnsley this season, keeping two clean sheets. "Jack is an excellent, experienced goalkeeper who has worked with (goalkeeper coach) Kevin Pilkington before," manager Rob Edwards told the club website. "He's got plenty of experience playing in the Championship with Barnsley, and we know that if anything were to happen to Ethan Horvath, we'd be very comfortable with the competition and cover in that area of the pitch, with James Shea coming back to fitness too."
Non-league Wrexham are still in the competition and face Sheffield United in a replay following their thrilling 3-3 draw