Sam Burgess could give the same boost to England at the World Cup as fellow code-hopper Sonny Bill Williams has to defending champions New Zealand, according to backs coach, Andy Farrell.

Burgess has raw power and physicality, but a lack of rugby union experience and just one season at Bath and 112 minutes of Test rugby. His case highlights the tendency to view rugby league converts as that of an impact substitute at the World Cup.

Burgess impressed off the bench during England's opening 35-11 win over Fiji last week.

Now a chest injury to first-choice centre Jonathan Joseph has opened up the possibility of Burgess starting in the crunch Pool A match against Wales at Twickenham on Saturday.

Farrell, who like Burgess made his name in rugby league before switching, believes the Bath powerhouse could provide England with the kind of dynamic midfield presence the All Blacks have come to expect from Williams.

"It depends whether you want to make the impact (off the bench) or make that impact from the start.

"The start of the game is pretty important as well; how you get off and how you make the other team feel," Farrell told reporters at England's training base in Bagshot, southwest of London, on Tuesday.

- More than impact -

"I wouldn't just pigeon-hole him (Burgess) as an impact (player), just like New Zealand wouldn't pigeon-hole Sonny Bill, would they?

"He's quite comfortable starting or coming off the bench and doing what's best for the team," Farrell added.

If Joseph is unfit England, who like Wales -- 54-9 winners over Uruguay last weekend - are due to announce their team on Thursday for a fixture in a 'Pool of Death' also featuring Australia, face a conundrum with Brad Barritt, Henry Slade and fly-half Owen Farrell, in his second string role of centre, all in contention for a midfield berth.

England coach Stuart Lancaster has used a remarkable 13 different midfield combinations since taking charge in 2012.

Meanwhile No 8 Billy Vunipola is pushing hard for a starting spot in place of Ben Morgan, doubtful with a knee problem, after making his mark off the bench against Fiji.

Last month, Wales coach Warren Gatland, before his side were beset by an injury crisis, said England were "not 100 percent sure of where they are going" and suggested they did not know their best team.

But Farrell said: "Everyone is so intrigued by selection because we're in a great position. Is it Billy, is it Ben? Is it Sam, is it Brad? Is it this, is it that?

"It's only like that –- people trying to work it out – because we have so many options –- but for us it is brilliant because we know they can all do it and they are pushing each other to do it."

Farrell added: "No-one says he (Joseph) is out.

"We are not worried about any scenario. That is why you pick the squad you do in the first place so that you cover all bases. We are 100 percent confident and comfortable with everyone, to have a proper good international team that can do the business."
Source: AFP