Stuart Lancaster has told Sam Burgess he must serve a successful union apprenticeship if he is to be selected by England, but offered a glimmer of hope he could be involved at the 2015 World Cup.

Burgess will begin a three-year contract with Aviva Premiership club Bath in October after a release fee was agreed with his NRL team South Sydney Rabbitohs.

So far the move has been funded exclusively by Bath, although Lancaster revealed the Rugby Football Union could yet be involved financially, stating: "I think there are discussions ongoing."

The decision of possibly the biggest name in rugby league to change codes has been greeted with excitement, although Lancaster has denied the 25-year-old will be fast-tracked into the England team.

He said: "Sam is going to have to earn the right like anyone else. It's going to be extremely difficult for a player to come from rugby league in October and then play in the 2015 Six Nations. But if he makes the transition smoothly and begins to play well during the second half of that season, then there is an outside chance he could make the World Cup training squad."

Burgess cited the 2015 World Cup when explaining his decision to switch codes and, at 6ft 5in and more than 18 stones, he has the physical attributes needed to make an impact with Bath and England.

Although a forward in league, inside centre appears his most likely position when he begins his career at the Recreation Ground. Number eight has also been mentioned as a possibility.