Kieran Gibbs and Conor Townsend are both doubts for the game following knocks.
Gibbs picked up a groin niggle against Derby County last weekend which Slaven Bilic expects to rule him out 'for a few weeks'.
Townsend has also suffered a knock that will only keep him out for a few days.
Nathan Ferguson is likely to play left-back against Blackburn Rovers tomorrow, with Darnell Furlong at right-back.
Club captain Chris Brunt will provide cover from the bench.
"We have a slight problem at left-back which is hard to cope with," said Bilic. "Gibbo got injured with an old injury, he’s had problems with his groin a few times. It’s nothing major but he’s out for a few weeks.
"Unfortunately Conor also felt something. This is a guy who didn’t miss one game last season, was available for every game. In a couple of days time he will be ok, but it’s one of those situations.
"Ideal is to have two players for each position, if you have three or four or five it’s happy to keep them all important. We have to find a solution within the squad.
"Darnell and Nathan played last week, they can do the job.
"And of course we have Chris Brunt. We can be calmer there then we would be with a couple of other players not available.
"He’s club captain and I spoke to him, he played left-back in the Premier League, he’s got a great cross, a great left foot."
When Furlong came on for Gibbs in the first half at Pride Park, he replaced him at left-back, but at half-time he switched flanks with Ferguson.
"We changed it because Darnell is more offensive and the left is not his side, if you have him on the left we don’t have big crossing assets," explained Bilic. "With this you can stop the opponent on the left and have a good solution on your right. It also depends who’s playing on the wing for your opponent."
Bilic used his injury problem at left-back to explain why he signed 37-year-old goalkeeper Ali Al-Habsi on Thursday.
He said "Look at what happened to our left backs, can you imagine if that happened to your goalkeepers? There’s no Chris Brunt! Nobody within can fill in.
"Like every other club we needed a third keeper, we have a great young kid, Josh Griffiths.
"He’s still too young, we’re going to protect him. He’s showing great talent and determination, he’s training 24/7.
"We’re happy with Sam [Johnstone] and [Jonathan] Bondy but we needed another one, for the competition, nothing is for granted here.
"Ali’s a goalkeeper of huge experience in this league, still in good shape, he can only help us. With quality and experience."
Josh Griffiths is one of three Albion youngsters called up into the England under-20 team today.
Jonathan Leko and Nathan Ferguson have also been selected.