Socceroos forward Archie Thompson trained strongly on Friday and is set to return as the Victory look to end a run of three losses when it hosts Newcastle Jets on Sunday afternoon at AAMI Park.
The Jets have given them a helping hand by resting marquee player Emile Heskey and striker Michael Bridges, while Thompson looks to have recovered from a hamstring injury.
"It's great to have him back in the side," Postecoglou said.
"He's an important part of what we do."
Postecoglou hasn't pushed the panic button after his fourth-placed team's 6-2 shocker against ladder leader Central Coast.
He said it was more important for it to peak for the finals with four rounds remaining after this weekend.
"Whatever happened last week or the week before, it's really important in the next five weeks that we hit our best form of the year," said Postecoglou.
"If we do that on the eve of the finals, it gives us the best chance to win the competition.
"There's no point in peaking today and not being right when the finals come around."
The coach said losing to the A-League's top three teams in its past three games was an "indicator" of where it was at.
Victory at least has an easy run home, meeting five of the bottom six clubs.
Postecoglou wasn't surprised the Jets opted to rest Heskey, given his 35 years and heavy travel schedule with four games in 14 days, and said he would have done the same.
The Jets are among five teams vying for the final two finals spots.
"If anything, they're going to have a fresh side out there full of running which will be a challenge for us."
Midfielder Zenon Caravella will also miss the trip to Melbourne with a hamstring injury he sustained against Phoenix, while Sam Gallaway is in major doubt after hyper-extending his knee.
"We can't afford to be really poor again," said Postecoglou.
"The most important thing for us is to get back to playing good football."