In his first competitive game since taking over at last year's relegated Molineux outfit, former Millwall manager Jackett also claimed star striker Kevin Doyle, who was not present at Deepdale, was costing the club too much in wages.
The visitors created the better chances with Bakary Sako going close on a couple of occasions but Preston new boy Kevin Davies was a constant menace.
Jackett, though, claims his new troops need to step it up if they are to bounce straight back to the Championship.
"In terms of the favourite tag, we have to make sure we do better on the ball, particularly in the second half because we didn't have a shot on target and that's where we can improve," said Jackett.
"It's no surprise that we'd be tagged (as favourites). In terms of a changing group and team, it shows that you are never quite sure what you have until you get out there and play.
"In terms of Kevin (Doyle), generally his wages are too high for where we are - that's common knowledge.
"Between now and the end of the window there will be interest in him but in the meantime he's not someone that I'm going to close the door on if he's fit and the team needs him.
"So, in summing up his situation, he's not someone that I've necessarily pushed to one side or overlooked but he is in a situation where I've not been planning with him because the expectation is that he will leave."