The Terriers have slid to 16th in the table and since beating Manchester United in October they have scored just twice in six matches.
But a fifth victory at the John Smith’s this season would see Town leapfrog Brighton, back in the top flight themselves after automatic promotion and currently two points better off in 12th.
“A must-win game is a final, where you have no chance to correct something and this isn’t the case on Saturday,” Wagner said.
“But it’s a massive game for all of us and a great opportunity in front of our supporters to play Brighton and be in front of them after the game.
“There are so many important stories in this game. This is why it’s a big game, but it’s not a must-win game because a lot more will follow after this.”
Wagner has no new injury concerns following last week’s 2-0 defeat at Everton, while winger Rajiv van La Parra sits out the final game of his three-match ban.
Huddersfield will come under increasing pressure if they slip to a fifth straight defeat, but Wagner insists he is comfortable with his side’s position in the table.
“If you had offered me 15 points after 15 games and then Brighton at home, I would say ‘absolutely'”, he added.
Paris Saint-Germain are reportedly ready to launch a summer raid for Chelsea left-back Marcos Alonso.
Terriers midfielder Phillip Billing has spoken about the whirlwind nature of his move from Denmark to Huddersfield as a teenager.
Malcom has admitted the time is right for him to leave Bordeaux and is dreaming of a move to German giants Bayern Munich.