"We know we can play football, we know we have the players on the pitch who can create chances," Forest's Chris Cohen told the Nottingham Evening Post.
"But we are going to have to go there and show different strengths again. The ball is going to be up in the air a lot - as it was at Walsall - and we just have to show our battling spirit.
"Any kind of win we can get is fine. We will take a scrappy win because then we can look forward to a tie against Liverpool."
Luton are currently in administration and Saturday's game against Millwall was rained off. Manager Kevin Blackwell however praised his side following their draw at Oldham last Tuesday.
"The lads have not been paid for six weeks. We are in administration but the lads went out and put in a thoroughly spirited performance," he said.