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.
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."
Former England international Davies saw a shot blocked by Carl Ikeme and came within inches of converting Will Hayhurst's cross late on.
And Preston boss Simon Grayson warned League One defences more was to come.
He said: "Kevin Davies is a handful, he uses his body extremely well, gets into good positions and wins a few free-kicks.
"Every centre-half will know they've been in a game come the end of the season when they've played against Kevin.
"He's got so much focus of what he wants to achieve and that will rub off on everybody throughout the club. Back fours will be quite daunted by Kevin.
"It was a good opening-day fixture for us. I think the game was on a knife-edge most of the time.
"There was a lot of endeavour and good attitude from both sets of players and the work-rate was there from our point of view.
"The first thing you want to do in the first game of the season is make sure you don't get beaten.
"I think we can be really pleased with how we performed. There were some good individual performances."
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- Kevin Doyle
- Kevin Davies
- Bakary Sako