Tom Curry and Denny Solomona were part of England’s recent training squad, while former England full-back Callard believes the likes of Will Addison, Sam James, Mike Haley, Ross Harrison, Ben Curry and Josh Beaumont are close to honours.
However, following last week’s 50-35 defeat at Wasps, Callard said: “There are a lot of good, young English players here but let’s not beat around the bush, they have to perform for Sale in the Premiership every single week.
“Whatever their England aspirations are, they have to perform damned well at home, but it’s even more important they perform away from home as well because that’s the level and quality of individual Eddie Jones is looking for.
“Guys like Sam James, Will Addison and Mike Haley really need to kick-on and demonstrate their capability. Will’s a fine player with a good kicking game and great leadership potential, while the Currys are in there making waves.
“But if they are going to break into the current England team, they have to step things up away from home.”
Callard left the RFU last summer after 12 successful years as a development coach, during which time England’s age group sides achieved unprecedented success, including an historic first Junior World Cup victory in 2013.
He believes Sale’s current crop of youngsters is among the finest he has seen and is confident that under the new ownership of Simon Orange and Ged Mason, the drain of players south to wealthier clubs will be reversed.
Callard said: “Sale are massive on youth development and the owners are very passionate about developing local talent.
“You look at lads like Cameron Redpath, Kieran Wilkinson, Sam Moore and Arron Reed, who’ve just returned from the England U18s tour of South Africa, and they’re as exciting a group of young players as I’ve seen.
“There’s a great academy set-up, led by Brendan Thomas, which is not just promoting the club within the wider community in the north-west, but also making it aspirational for these youngsters to play for Sale.
“It’s not the case that if players want to be a professional or play for England they have to head south, if you want to achieve your ambitions it’s here on your doorstep.
“The Curry boys are 19 and they’re playing Premiership rugby and being involved by England. The fact they signed five-year contracts in March shows Sale’s intent and we can stop the player drain by being aspirational.”
Callard is delighted to be back in coaching, adding: “I had a fabulous 12 years at the RFU and intended to take a year out. But I got itchy feet, Sale came calling and I’m really enjoying the positive vibe at the club.