Alan Dickens says it is ‘fantastic’ for Saints to have three players in England’s World Cup squad.
And the defence coach has hailed the hard work of Lewis Ludlam, Courtney Lawes and Piers Francis after they booked their place on the plane to Japan.
Ludlam only won his first cap last Sunday, starring as England beat Wales 33-19 at Twickenham.
But it proved enough for the 23-year-old to be named in his nation’s 31-man group for the big tournament, which starts in September.
Francis and Lawes, who, like Ludlam, shone for Saints last season, will also be there.
And Dickens said: “It’s fantastic for us at the club, and obviously for the players.
“It’s testament to the hard work those lads have put in over the last 12 months to get on the plane.”
On Ludlam, Dickens said: “He keeps coming back from these little setbacks.
“He told me last season that he was released as a 15, 16-year-old and the character he’s shown during this past year he showed then.
“He went away, worked at what he needed to work at and came back into the Academy.
“He’s had a couple of shoulder injuries, he’s broke his leg, and he plays in an attritional position in the back row.
“He’s been unfortunate with a couple of injuries and that’s slowed him in terms of progressing, but he’s taken his chance in these past 12 months.”
And Dickens believes the presence of South Africa flanker Heinrich Brüssow at Franklin's Gardens has been a big help to Ludlam.
"One of the things Lewis has done is worked very closely with Heinz Brüssow in this past year, especially on his breakdown work," Dickens explained.
"Rugby's a late developing sport and Lewis is still young. He's 23 and he's broken into the England squad at that age, which I think is relatively young for a forward.
"He had a really good season, stayed relatively injury free, put a run of games together and hit a run of form.
"He's been rewarded for that."
Francis has five caps to his name.
And Dickens said: “Piers’s defence at Twickenham last Sunday was solid.
“If you work with Piers you know what he brings.
"Everything he does is for the best of the team and those qualities have shone through at the World Cup training camp."
And on Lawes, who has become a key man for club and country, Dickens said: “I've got nothing but admiration for Courtney in terms of his ability. When he's on his game, he's world class.
"I did enjoy watching him pack down at seven towards the end of the game last Sunday. It showed his ability.
"Yes, he's a second row, but we've played him in the back row in the past and he just slots in there.
"He knows his role and he gets on with it.
"He's very unassuming around the place but very, very switched on when it comes to performing at the weekend."