South Africa's most capped lock Victor Matfield says England's litany of injuries in the second row could hinder their line-out in the Six Nations.
Second row forwards Courtney Lawes, Geoff Parling, Joe Launchbury and Ed Slater are set to miss at least the 6 February game in Wales.
"The biggest problem will be that two of those guys probably run the line-out," Matfield, 37, told BBC Sport.
"I'm sure the Wales boys will go in targeting the line-out."
Matfield added that he expected Wales to also focus on "the driving mauls at the line-out. The second row give team-mates confidence in the line-out and when they're gone, a lot of guys don't have confidence in the new guy.
"You need to identify who is going to be the line-out captain and give him that responsibility to get the guys to believe in his calls."
With British and Irish Lion Parling, who will leave Leicester for Exeter next season, having missed the autumn internationals with concussion, Bath's Dave Attwood lined up alongside Lawes in the second row for all four of England's November Tests.
But Lawes and Parling are poised to miss at least the Wales game at the Millennium Stadium because of injury, while Launchbury and Slater could be out until April.
England head coach Stuart Lancaster will have to select two from Attwood (16 caps), Saracens' George Kruis (four) and the uncapped pair of Leicester lock Graham Kitchener and Northampton Saints' Christian Day, for his second-row pairing next week.
"Courtney Lawes has been outstanding. I still believe there is the option of playing Parling at five and Lawes at four [when they are fit]," said 121-cap Matfield, who won the 2007 World Cup with the Springboks.
"Parling would probably be the better line-out organiser, but Courtney is a very physical player, so those two guys stand out for me."
|England's Six Nations fixtures|
|6 Feb: Wales v England, 20:05 GMT|
|14 Feb: England v Italy, 14:30 GMT|
|1 Mar: Ireland v England, 15:00 GMT|
|14 Mar: England v Scotland, 17:00 GMT|
|21 Mar: England v France, 17:00 GMT|