West Brom have three Premier League home wins this season - the most recent against Newcastle on New Year's Day - and one victory since Mel's January 9 appointment.
Mel, whose side lost at Hull last weekend, hopes a stronger defensive display can provide the foundations for another win against south Wales opposition after the defeat of Swansea earlier this month.
"The way we're approaching the game is to be defensively strong," Mel said on wba.co.uk.
"It's been quite a long time since West Brom have kept a clean sheet.
"We've been conceding some very early goals and that means we have to put a lot of effort in.
"In a lot of the games at home we have gone in at half-time 1-0 down and that means we need to put in extra effort.
"That's why we have highlighted the kick-off against Hull.
"If you look at the video it shows within two seconds of kick-off we lost the ball.
"You simply cannot lose the ball in the first moments of the game - it was a counter-attack and a cross, which nearly produced a goal.
"This is exactly why we are working hard to make sure this does not happen."
Mel has no doubts on his team's attacking capabilities, but winning is down to a resilient rearguard.
"We're very capable of creating scoring opportunities and we're convinced, if we don't concede, we'll be able to win the game," he added.
"It's obvious if we concede fewer goals we'll have greater opportunity because we're a team from midfield going forward that create opportunities and are successful in that."
Striker Victor Anichebe faces a fitness test on a hamstring problem.
Mel added: "He is an important player for us and if he doesn't play from the start we'll try at least to get him on the bench to come on.
"But we also have (Saido) Berahino, (Matej) Vydra, Thievy (Bifouma), (Stephane) Sessegnon and (Zoltan) Gera - all players who are capable of playing that role."
Gareth McAuley (ankle) should feature, Morgan Amalfitano and Diego Lugano (both knee) are back in training and could feature, but Claudio Yacob and Billy Jones (both hamstring) are out.
Jonas Olsson completes his two-match ban, while captain Chris Brunt (knee) remains out.
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