Williams, 25, joined Liverpool's academy at nine years old and spent 16 years at Anfield before the club confirmed last month that his contract would not be renewed.
He made 19 first-team appearances in his one significant campaign — a breakout season in 2020-21 when he partnered Nat Phillips to help Liverpool navigate an extraordinary defensive injury crisis and secure a third-place Premier League finish.
Since that season he has made five loan moves — to Swansea City, Blackpool, Aberdeen, Port Vale and Morecambe — without fully establishing himself at any. His most productive spell came at Morecambe in 2024-25. He did not play a competitive senior minute for Liverpool last season, appearing just once as an unused substitute in a Carabao Cup tie in September.
Williams announced his departure on social media last month: "From signing as a 9-year-old boy, to leaving as a 25-year-old man. This club has let me fulfil things that dreams are made of. It's been an honour to wear this shirt, rub shoulders with legends and play for the greatest set of fans in the world. Thank you Liverpool, YNWA."
The trial at New York Red Bulls was reported by The Athletic's Tom Bogert. No formal deal has yet been confirmed.
A move to MLS would give Williams the regular first-team football he has been unable to secure in England. The Red Bulls have a track record of signing English players and have links to several European club academies through their Red Bull ownership structure.