The pair have been subject to interest from other clubs, although no deals for a move away from Huddersfield have been struck for either player.
Fulham and Sheffield United have both reportedly shown an interest in Kongolo while West Bromwich Albion are believed to be keen on securing Grant's signature.
Head coach Carlos Corberan will not be including the duo in his squad for Saturday's Yorkshire derby against the Millers, in keeping with what he has done for previous fixtures during his short time in charge at the Terriers.
"I don't know the situation because I don't control the market," said Corberan on the futures of Grant and Kongolo.
"A lot of the time, clubs wait until the last moment to make their final offers but I don't know if that is going to be the case with these two players.
"The situation with those players is the same, they both have options to move but have the option to stay if they don't make a deal with another club.
"Right now, they are not going to be involved in the next game."
The Terriers secured their first victory under Corberan last week as they recorded a 1-0 success over Nottingham Forest.
They were without Christopher Schindler and Lewis O'Brien for that fixture while Jonathan Hogg was substituted in the first half due to injury.
Hogg and Schindler could feature against Rotherham this weekend, while O'Brien is likely to return after the international break.
"We don't know at this point how he is going to feel," added Corberan on Hogg's fitness.
"He is a competitive player for us and he always wants to be with the team but now we need to wait until tomorrow.
"The situation with Lewis O'Brien is the same as last week. I hope he can be back in normal training next week and then take advantage of the international break. If he can train for two weeks with the team then we hope he is going to be ready.
"With Schindler, he was in training today [Thursday]. We need to see how he's reacted and what options he has tomorrow but we don't want to risk more injury.
"It is important to have available players, not only for this game but they need to be available to help the team in consecutive games. The reaction of his body will tell us if he can play or not.
"Danny Ward is another medium-term injury and we hope he's in the last part of his recovery but we need to see."
Meanwhile, Naby Sarr could make his first appearance for Town since joining from Charlton Athletic.
The player had two weeks in quarantine after signing for the Terriers Corberan added: "He's completed a normal week this week and has worked in the tougher part of the week. He is one player who will be ready for the squad for this weekend.
"If he didn't bring something different we wouldn't have bought him."
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