Remi Garde's men host Manchester City in the FA Cup fourth round on Saturday afternoon.
Hutton has been sidelined since injuring his hamstring in the 3-1 defeat at Sunderland earlier this month, while Sanchez is also struggling with the same issue as the Scottish right-back.
The 29-year-old Colombian midfielder originally picked up the injury in the 1-1 Boxing Day draw with West Ham United and missed the next five matches while building back to full fitness.
He subsequently made his comeback in last week’s 2-0 FA Cup third round replay win over Wycombe Wanderers but was forced off at half-time after suffering a recurrence of the problem, sitting out the following 0-0 draw at Midlands rivals West Bromwich Albion as a result.
He has still not fully recovered over a week later and has now been ruled out of Saturday’s match at Villa Park along with Hutton and long-term absentees Jordan Amavi and Adama Traore.
Speaking to reporters, Garde said: “[Those who] won’t be fit for selection are Alan Hutton and Carlos Sanchez.”
However, one player who is finally fit and available is Gabby Agbonlahor.
The long-serving striker has struggled with calf and back injuries over recent weeks but had also been out of the first-team picture beforehand, having seen just one minute of action since Garde replaced Tim Sherwood as Villa boss in November.
Reports have recently linked the 29-year-old with a move to Turkish side Kayserispor amid claims that he could be allowed to leave his childhood club on a free transfer [h/t Daily Mail], but Garde seemed to rule out the prospect of an imminent departure at his press conference.
He even suggested that the Birmingham-born forward would have a chance to regain his place in the side if he shows enough in training over the coming weeks, telling reporters: “When I arrived Gabby was injured and was not in the training sessions for a long time. The time I spent discovering the team and players he was not here, unfortunately.
“He has trained for the last week and seems to be better. Of course, if he's in the right mood and okay physically he could give us a lift to score goals.”
Nevertheless, the Frenchman stressed that he would not be making significant changes to his side for the visit of Manuel Pellegrini’s men, adding: “It’s a very important game for us. Playing Manchester City is a big opportunity for us. We are in a good momentum at the moment and it’s very important for me that the players keep that.
“Whoever plays the game, it will be important to give their best, but I’m not sure I will change the team too much.”