Six of Leeds' remaining 10 games in the Championship are at home, with the rearranged fixture against Peterborough followed by the visit of West Yorkshire rivals Huddersfield to Elland Road on Saturday.
"We've had a tough week this week and we could have come out of it with six points," Warnock told the club's official website.
The Leeds boss said at the start of the month that Leeds' three fixtures, at home to Millwall and then at Leicester and at Crystal Palace, held the key to his side's chances of forcing their way into the top six.
Victory over Millwall set Leeds on their way, but they conceded late equalisers at the King Power Stadium last Tuesday and at Selhurst Park on Saturday to be left with five points from those three games.
"I said at half-time I thought we could win the game, not just get a draw," Warnock added on the Palace game.
"I thought we really went out and gave it a good go with two good goals from Steve Morison. We should have finished it off again, Ross McCormack had a great chance to make it 3-1. Similar to Dave Norris, the other night, who had a great chance to make it 2-0 at Leicester.
"We have had a tough week this week and we could have come out of it with six points. We've got to keep the way we are playing at home on Tuesday and the fans get behind us.
"They're all important games now, we'll say it before every game. The next one is the vital one."