Sam Burgess during England training© David Rogers/Getty Images

England head coach Stuart Lancaster views Sam Burgess as a centre rather than flanker and will only consider him for the World Cup as a midfield option.

Burgess, who switched codes in October, played his best rugby as a back row for Bath last season including a run of six starts in the number six jersey that culminated in the Aviva Premiership final.

The 26-year-old's success as a destructive blindside flanker appeared to end the debate over what position he should fill following a sluggish start to his union career.

England's line-out requirements, however, and the removal of Manu Tuilagi from World Cup contention on disciplinary grounds have compelled Lancaster to restrict his thinking on Burgess to the centre.

"We're into the rugby stuff now and I had a long conversation with Sam about his position. For two reasons we see him as a centre," Lancaster said.

"In the back row we need our sixes to be effective in the line-out and there are some big players in our line-out calling structure. Tom Wood, for example, is the third most thrown to forward when he's played and James Haskell we've also used quite a lot. Tom Croft is nearing fitness now as well.

"We've lost [hooker] Dylan Hartley and with him some experience when the line-out is a big part for us. It would be a real stretch for Sam to be competitive in that position.

"Also, Bath have used him as a forward but his effectiveness has been in the middle of the defensive line and as someone who takes the ball to the line as a carrying threat.

"Without Manu in the backline, we need options that give us physicality. We're confident from what we've seen that he'd be capable of competing at centre.

"Centre is where he's been running with us and that's where we'll see him training right until the final 31 are selected. But it's a competitive position when you see the options we have in the position."

Lancaster was speaking from Colorado, where England are six days into their two-week training camp at altitude as the countdown to the World Cup opener against Fiji at Twickenham on September 18 continues.

Following three weeks of conditioning work at Pennyhill Park, the squad has started rugby-specific training at the home of American football team the Denver Broncos with their first warm-up match against France looming on August 15.

Number eight Ben Morgan is on course to face Les Bleus at Twickenham as his recovery from a broken leg gathers pace, but back row colleague Nick Easter must heal a back problem before he can be considered.

"Next week is a big week for Ben," Lancaster said. "We probably won't put him straight into the full contact sessions, we'll stagger that, but there should be no reason why he wouldn't be passed fit by the end of next week. Everything is bang on track with him.

"I had a good conversation with Nick and it was hugely disappointing for him to pick up the injury on what was effectively day two of the camp. My intention was always to bring him here.

"However, there was no point in that when he couldn't train, so the most sensible thing was to leave him at Harlequins. It's not ideal, but we've certainly made no decision yet and we won't make one until nearer the time."

The deadline for teams to name their final 31 is August 31 and Lancaster insists there are still places in England's squad available.

"There's a long way to go and the players know the stakes are high in terms of selection. Every training session and moment counts," Lancaster said.

"There are definitely places up for grabs and there are some guys on the fringes who are putting their hands up. We'll narrow the numbers down during August and by that second France game we'll need to know the 31."