Calderwood will be playing for Hull next season
Winger Mark Calderwood has spoken of his relief that his gamble to choose England ahead of Scotland was rewarded with a World Cup call-up by Tony Smith.
"I could have ended up with egg on my face," said Calderwood, 26, after being named in coach Smith's 24-man squad.
"Tony said he couldn't guarantee anything and I could have not been picked for either.
"I would have been proud to play for Scotland but playing for England is a different level."
With Scottish grandparents, Calderwood could have played for Scotland but he opted to choose England when he was offered a place in the initial train-on squad.
His England call-up follows a difficult season for Calderwood after he was told his contract with Wigan would not be renewed.
But he landed a two-year deal with Hull which gave him a new lease of life, culminating with a superb display for Wigan in the final play-off eliminator against his former club Leeds.
"It's not been the best year for myself," said Calderwood. "I was in and out of the Wigan team. But the last six weeks I've dug in and that's obviously why I've been picked.
"I didn't know if I was staying or going but when it came out that I was going to Hull, that took a weight off my shoulders and kicked on from that.
"It's obviously not nice when they say they're not going to keep you but I've moved on now.
"I had some people to prove wrong and I will be trying to do that in Australia."
And Smith said that Calderwood was chosen ahead of Hull KR winger Peter Fox because of his recent form.
"Mark is a player I've a lot of time for," said Smith. "I've had the pleasure and privilege of coaching him myself and I know what he's capable of. I think he showed that to the public over the last few weeks.
"I think everybody recognises his try-scoring ability but he probably highlighted in the last game his try-saving ability, which is something I've known for a long time."