Video: Castleford Tigers' boss Daryl Powell looks to accentuate the positives

Wigan Warriors announced yesterday that two of their England internationals, the prolific winger Josh Charnley and exciting centre Dan Sarginson, will leave at the end of the season.

Charnley, the 24-year-old who has scored 148 tries in 152 games for the club, will switch codes to join Sale Sharks hoping to emulate the last Wigan winger to make that same move – Jason Robinson.

Meanwhile, Sarginson, 22, becomes the latest England international – tenth in total – to relocate to the NRL having agreed a two-year deal to follow the likes of Sam Burgess, James Graham, Josh Hodgson and former Wigan team-mate Joe Burgess.

Losing further such talents from the domestic league here has, inevitably, re-opened the debate about the best way to retain leading players and discourage them from being lured to Australia or rugby union.

Increasing the salary cap would be the easy solution but Powell, who played in Sydney and at the Gold Coast during his own career, said: “I don’t know how much of that (Wigan exits) is about money.

“You talk about different challenges and that’s always going to be an option for players.

“I had a go in rugby union myself (as Leeds Carnegie coach) and I think it’s the new challenges that are interesting for people. I’m not sure if that would change with the cap going up. But obviously we don’t want to be losing our better players to other sports. How you keep those guys I don’t know.

“There’s plenty who have gone out and pretty soon come back (from union) but I don’t think the salary cap would make a big difference.

“I know there’s debates about making it a little bit bigger at the moment partly with the challenge we’ve got with the NRL but I don’t know if clubs can do it.

“It’s there for a reason.”

Furthermore, players featuring in the higher-intensity NRL should also improve England’s chances of success.

“We want to win something as a nation,” added Powell.

“We’re certainly developing really good quality players. You can see that.

“Elliott Whitehead’s gone over (to Canberra Raiders) this season and is playing really well.

“Whenever players do go over to Australia you see there is no difference (in ability).

“The big difference is the amount of quality of players we have got and in some ways you could argue it (stars leaving) is positive as more young players will probably get an opportunity,” he added.

“They are only going to get better with experience.”

Meanwhile, leading referee Ben Thaler, who took charge of the Grand Final and Challenge Cup final last season, has no Super League game this weekend and will instead take charge of Bradford Bulls v Sheffield Eagles in the Championship.

He refereed Castleford’s match in France and was heard on Sky Sports questioning one of video referee Thierry Alibert’s decisions with the official and Catalans stand-off Todd Carney.