Sam Burgess admits he’s finding the transition from rugby league to union more difficult than he anticipated.

“I knew it was going to be tough but I didn’t know it was going to be as tough as this,” former NRL superstar Burgess told Fox Sports News.

“But I came for the challenge and it certainly delivered that. I’ve no regrets.”

The 25-year-old made his first starting appearance in the English Premiership on Sunday, playing at outside centre in his Bath team’s 17-8 loss to Leicester.

Having also played at inside centre and loose forward in his handful of matches since overcoming his NRL grand final injuries, Burgess remains hopeful of being in the mix for England’s squad at this year’s World Cup.

But he acknowledged he’s still a long way from reaching the sort of level he achieved in his league days.

Burgess’ only previous experience of rugby union was at schoolboy level.

“There are so many differences,” he said.

“In fact I would say they are almost opposite, apart from playing on the same-shaped field and with a same-shaped ball.

“The way we tackle in league is different to how you tackle in union and the opportunities (to score) are probably not as great as in league.”

England coach Stuart Lancaster watched Burgess against Leicester.

“I would love to be a part of the England squad but I can’t talk my way into the team,” Burgess said.

“I’ve really got to get out on the field and prove myself.”

Burgess appeared to enjoy the time he spent in the forwards.

“I’ve enjoyed the scrummaging just because there is a bit of contact and good camaraderie amongst the pack and I quite like that,” he said.

“There is a bit of a build up for each scrum, a bit of backside slapping.”