Routledge, who played with the Hull City midfielder at Tottenham Hotspur, believes that the 27-year-old should be considered for a spot in Roy Hodgson's World Cup squad.
"For me he should be in contention for the World Cup, but I am not the manager of England," Routledge told reporters ahead of Swansea's game against Hull on Saturday.
"They pick their team how they pick it, but he has got the talent and ability to be around that squad, there is no question of that in my mind.
"Tom is one of the most underrated players in the league. I have never seen anyone do what he can do with both feet with a football."
Huddlestone has played four times for England, with his last appearance coming in 2012.