The Bluebirds made a stellar start to the new Championship season, winning their first five games on the bounce to lead the way in the early standings.
Warnock's charges were held to a 1-1 draw at Fulham on Saturday, however, and were stunned by Preston at Deepdale last night in a contest that the hosts dominated from start to finish.
"It's no excuse because the goals were terrible, but we had eight or nine lads not at the game," Warnock told reporters afterwards.
"The travelling we've done since Saturday – without it being an excuse – is more than any other team in the country and it's not a coincidence there's nine or 10 lads not at the races.
"We were second best all night and if we hadn't had been undefeated I would have made three or four changes.
"I blame myself quite a lot for not doing it, but it's difficult when you haven't lost. Hindsight's a great thing but you're a brave man to make changes when you've not lost a game – but that's out of the way now and I can make changes when I see fit now."
Next up for the Welsh side is a home encounter with Sheffield Wednesday on Saturday afternoon.