Elliot Daly celebrates his Wasps try against Saracens© David Rogers/Getty Images

Wasps rugby director Dai Young believes in-form stars Joe Simpson and Elliot Daly will struggle to crack England's squad in time for the World Cup.

Both players shone in Wasps' battling 32-18 Champions Cup quarter-final defeat at Toulon on Sunday, but Young claimed they are "up against it" to convince head coach Stuart Lancaster they merit World Cup inclusion.

"I think they're up against it going on discussions I've had, but from my personal point of view I don't know what more they can do," said Young.

"Consistently Joe Simpson has been outstanding both in attack and defence this season, and his kicking game is a real plus, but in broken play as well he's a real threat.

"I think the criticism a season or so ago was his game management not him as a rugby player, his game management, his decisions of when to run, when to kick and when to pass.

"And I certainly think he's mastered all that, so whether he'll edge his way in I'm not sure.

"Do I think he should be there? Yes I do. Would I swap him for another nine? No I wouldn't. So that's how strongly I believe in him."

Quick-witted scrum-half Simpson has just one England cap despite performing among the Premiership's top half-backs for years.

For all his speed and attacking verve, Simpson is potentially Lancaster's fifth choice scrum-half, certainly behind Ben Youngs, Richard Wigglesworth and Danny Care in the pecking order, with Lee Dickson also highly regarded by Lancaster.

Daly, an under-20 World Cup winner with England, tested Toulon's defence with a host of telling breaks on Sunday and had a hand in both of Will Helu's tries. He has long been viewed as a prodigious attacking talent but one harbouring questionable defence.

However, Young believes his midfield tyro has spent the majority of this season addressing those defensive concerns, and backed the Barbarians star as a future challenger to Jonathan Joseph's England berth.

"I think Elliot Daly has just gone from strength to strength this season again," said Young. "Last season there were a few stones thrown at him about his defence but his defence was outstanding again [against Toulon], and at the end of the day you've got to go and win games.

"You get the ball into Elliot's hands and things happen. He's got the ability to get on the outside of people, to really cut defences and obviously clean his winger on occasions. So any team that wants to score tries, any team that wants to cause teams problems, Elliot Daly's a constant threat whenever he has the ball.

"We're absolutely thrilled with the way he's playing. I think Jonathan Joseph has done an excellent job for England but I think he's shown the way. That you need that threat at 13.

"And I'm not suggesting Elliot should leapfrog anybody but certainly that's got to be the way we play, and Elliot's certainly going to be up there pushing JJ all the way.

"Whether they'll be in there I'm not sure, but you've got to go out and win games and these players will go out and win games for you."