Fax can leapfrog Salford into top spot in National League One if they beat the Rams by 15 points or more, while the heavy woollen outfit are still looking for their first league victory of the year.
But Calland, who has added fit-again backrower Danny Heaton and powerhouse wingman Andy Smith to the 17 that thrashed Batley last time out, is keen to guard against over confidence.
"For me, Dewsbury are in a false position," he said, who watched his side win 36-34 at Rams Stadium on Easter Monday with the help of a last-play call from referee Gareth Hewer, who ruled out what would have been a winner for the home side.
"They are certainly not a bottom of the table team.
"I watched them against Widnes a couple of weeks ago and they were the better side for long periods of the game.
"They could have easily beaten us over Easter - I've certainly seen tries like that given, put it that way - and they pushed Celtic Crusaders all the way at Bridgend.
"They are really close to a win, and we have to make sure it doesn't come against us tomorrow."
Dewsbury will also be under new management tomorrow, with Calland's former Bradford teammate taking the reins - in the short term, at least - from the axed Andy Kelly, who left the club on Tuesday.
"Warren has come in this week and he will have them really motivated to do well," said Calland.
"He's a good coach and I am sure their players will respond to him.
"He's also thrown our plans out a bit because we won't know how they are going to approach the game.
"They'll know plenty about us though, because he watched us train before the reserve game at the Shay on Thursday night and he looked to be making plenty of notes.
"But we've prepared well, and we will focus on how we perform and how we present ourselves.
"If we do that, I am sure the performance will follow."