Wales assistant coach Rob Howley wary of England's Sam Burgess
Wales assistant coach Rob Howley has described Sam Burgess as "an imposing figure" ahead of the former rugby league star's expected elevation to World Cup starting duty on Saturday.
Wales look set to face a reshaped England midfield of Owen Farrell, Burgess and Brad Barritt in the Pool A showdown at Twickenham.
While neither England head coach Stuart Lancaster nor his opposite Wales number Warren Gatland will announce their starting line-ups until Thursday, speculation is rife that Burgess has nailed down a starting place after just 112 minutes' Test match rugby union experience.
"Andy Farrell (England assistant coach) introduced me to him on the Lions tour in 2013," Howley said. "He's an imposing figure.
"I was impressed when he played with (Henry) Slade against France (last month). His ability to run hard lines and having that creative edge outside makes it more difficult defensively.
"It is important when playing against players like Sam to close down their space. It will be a challenge if Sam is playing at 12 at the weekend."
Asked to assess the difference between Farrell and the man he is set to replace, George Ford, Howley added: "George has been immense for England, with his ability to play ball in hand.
"Owen is great with ball in hand, his running threat and his kicking is very good. He likes pressurised games. It's nice to have that choice, and I am sure Stuart Lancaster and his coaching team will get that right."
If Lancaster opts for Burgess and Barritt, though, they will chronically lack experience as a partnership, certainly in contrast with the Wales centre pairing of Jamie Roberts and Scott Williams.
"With the speed of the game internationally, it's about that moment when you know how to react to that player outside as you run those lines so often in training and games," Howley said.
"We're fortunate to have Scott Williams, who has played and trained with Jamie for the last four years."
Gatland will reveal his starting XV on Thursday morning, and injuries permitting, there appears to be just two major selection debates.
The New Zealander must decide whether to retain an out-of-form Alex Cuthbert on the wing or go for 20-year-old Newport Gwent Dragons back Hallam Amos, while the hooking berth is a straight battle between Scott Baldwin and Ken Owens.
Full-back Liam Williams looks set to line up this weekend after taking part in training on Wednesday. Williams suffered a knock to his thigh during last weekend's 54-9 Pool A victory over Uruguay.
Wales, though, are still waiting on props Samson Lee and Paul James, who both went off in the Uruguay game after experiencing tight calf muscles.
"Liam trained fully this morning (Wednesday) and is ready to go," Howley added. "Our two props are still being assessed.
"Samson is further in front than Paul. We'll just have to wait and see. With our medical team we've got, we trust in them making that call. There are props on stand-by. We're waiting to make that call when we need to.
"We have already contacted Rugby World Cup, and there is special dispensation for front-rows which allows us to bring someone in even 24 hours before a game."
And looking ahead to the game, Wales lock Alun-Wyn Jones said: "We will step out into the storm in a couple of days' time.
"We have people who have been involved in games of this magnitude before, and others who haven't, and in there somewhere we will have a nice balance to prepare us for the game. We will look at ourselves before anyone else."