The club has a genuine chance of reaching a lucrative quarter-final given they face a fellow Championship side in the last 16.
“Hopefully we’ll be able to welcome a couple of players back for Dewsbury but we’re not in a position to finalise a 17 yet,” said Grix, who, with Sunday’s 46-10 success against Rochdale
Hornets, has completed back-to-back wins since Richard Marshall’s surprise exit.
“It is only a short week with one proper session on Tuesday night and then the team run Thursday.
“We could have Q (Quentin Laulu-Togaga’e) back and possibly Ben Kaye which would be a real help having their experience as it is going to be a tough game.
"Dewsbury are a big side and with this weather (rain) thrown into the mix I do think it will be a tight contest.
“We improved a little bit at the weekend but we need to be better again if we’re going to progress.”
Halifax are eighth in the Championship and sit two places but seven points above Dewsbury who have won just three games all season.
Grix – who hopes to soon hold talks with the board about taking the position on a permanent basis – will not be available himself and neither will be his brother Scott following his loan move from Huddersfield Giants.
“I have a groin/pelvis issue that’s lingering and taking over (coaching) has slowed it down,” he said.
“Time has been prioritised to leading training over rehab.
“Scott isn’t available but we can revisit his Challenge Cup availability depending on the results of both our game and that of the Giants.”
Meanwhile, along with Shaun Wane and Richard Agar, Richard Marshall has been made one of the favourites to take over as Leeds Rhinos’ new head coach following Dave Furner’s shock sacking on Tuesday.