The Dundee native is a product of Strathallan School, guiding his side to a Schools Cup final victory over Glenalmond College in 2018.
Nephew of former Glasgow Warriors head coach Sean Lineen, Walker represented his country at both the 2018 and 2019 World Rugby Under-20 Championships.
The tight-head made his professional debut in a 35-24 victory over the Sharks at Scotstoun, coming off the bench for the final 15 minutes of the bonus-point win.
His first start came in a 30-17 victory over Edinburgh at Scotstoun in March 2022, at the end of a week that saw him called into the senior Scotland squad for the first time.