Despite being just 17, full-back Shaw's performances in the Premier League for the Saints this season is said to have impressed the likes of Manchester United, Arsenal and Chelsea.
His displays have also resulted in him being linked with a place in the England squad for next year's World Cup in Brazil, something that Puncheon believes could happen.
"Luke will definitely play for England definitely no shadow of a doubt. He is England class and must have an outside chance of going to Brazil," The Mirror quotes him as saying.
Shaw has been tipped to be part of the England Under-21 squad for this summer's European Championships.