The pair completed loan moves to Spurs in the days leading up to the transfer window closing and could be thrust into action for the second leg of the semi-final, which the Londoners currently lead 1-0 following last month's encounter.
The visitors to Anfield are, however, unlikely to have centre-backs Micky van de Ven and Cristian Romero available, while Trent Alexander-Arnold is the only Reds player ruled out.
Tottenham boss Ange Postecoglou said: "In terms of availability from last week, everyone is fine, everyone got through OK, so no issues there in terms of that squad.
"Obviously Kevin and Mathys are both available. They've trained and are cleared to play, so that's all good.
"With Micky and Romero to a certain extent, I kind of feel like we've just got to be a bit more conservative with them.
"Micky got through the [Elfsborg] game all right but I don't think he feels he's ready for that sort of step up to [the] Premier League, the intensity of it – same with Romero."
Dominic Solanke, Wilson Odobert, James Maddison, Destiny Udogie, Timo Werner, Brennan Johnson, Radu Dragusin and Guglielmo Vicario are set to remain sidelined for Spurs.
Alexander-Arnold's absence comes after he was forced off in the second half of Liverpool's Premier League victory at AFC Bournemouth last weekend.
"I think you saw that he left the pitch with a bit of a pain in his leg, so that's why he misses the game tomorrow," Arne Slot told reporters at his pre-match press conference.
"But he is already on the pitch, not with the team but with the rehab coach, so let's see how long it is going to take. But he will not be available tomorrow."
Alisson Becker was in goal for the first leg at Tottenham Hotspur Stadium on January 8, with Caoimhin Kelleher on the bench.
Speaking on Wednesday morning, Slot admitted he has made a decision about which goalkeeper will start the 8pm GMT kick-off – but would not disclose his selection to the media.
Cody Gakpo and Jarell Quansah are the only players to have started all four of the Reds' Carabao Cup fixtures so far this season.
"If you reach the semi-final against Tottenham, you know it's going to be a difficult one," Slot said about overcoming the deficit. "But I think we will be better than the last time as well."
Last match
Bournemouth 0-2 Liverpool (February 1): Alisson, Alexander-Arnold, Van Dijk, Konate, Robertson, Gravenberch, Mac Allister, Salah, Szoboszlai, Gakpo, Diaz.
Brentford 0-2 Tottenham (February 2): Kinsky, Porro, Gray, Davies, Spence, Bentancur, Bissouma, Kulusevski, Moore, Son, Richarlison.