Spurs have been beset by injuries and suspensions over the past month, which has seen them plummet down the Premier League table amid an inconsistent run of form.
A thrilling 4-3 win over Manchester United in the Carabao Cup quarter-finals last Thursday was followed up by a humbling 6-3 loss at home to Liverpool on Sunday.
Ahead of a Boxing Day trip to Nottingham Forest, Postecoglou confirmed the club aim to boost their depleted squad.
"Like I said a while ago, we've been planning. A lot of it was going to be around where we're at around this time. Fair to say we're still a little bit short in a couple of areas and we need to reinforce," Postecoglou explained.
"January's trickier in terms of what sort of players you can bring in. For us, ideal - for any club, I guess - you want to bring in people who are going to make you stronger.
"I think the fact that, obviously, we're still in the Carabao Cup semi-final, still got Europe, FA Cup, we're in all the competitions, it's not like our schedule's going to ease up at any stage. So, I think it makes sense.
"We will try and reinforce. Where and what number we'll have to wait and see.
"You don't just want to panic and bring in anybody that you don't think will help our cause in the back half of the year, but I think we've already shown we are pretty methodical and prudent about our work. We'll make sure we'll bring somebody in who is going to help us."
A painful three-goal loss at home to Liverpool means Tottenham will be 11th on Christmas Day after three defeats in their last five Premier League, whilst they have also juggled cup commitments.
The context around those defeats is a lengthy list of absentees, which includes goalkeeper Guglielmo Vicario and key defenders Cristian Romero and Micky van de Ven.
Postecoglou added: "I can't be critical of this group of players at the moment in any sense. I think it would be unfair for anyone to because what they're doing is they're giving absolute maximum effort.
"That's backed up by the physical parameters you put against what they're doing. They're trying to do it in the way that I'm asking them to.
"So how can I be critical of that? I think that would be hypocritical of me. The players are doing their part. They're doing it to the maximum of their ability and it's a credit to them.
"I still think in the long term that's going to hold us in good stead."
Tottenham will be boosted by the return of Rodrigo Bentancur at Forest after a seven-match domestic ban for racist remarks but Postecoglou will not be able to celebrate the availability of one extra player with family on Christmas Day.
"No, it's a family tradition mate that I'm on my own. The family is in a warmer climate in Australia with family," Postecoglou revealed.
"We have a couple of young boys, so it's important they are around family at this time. I will give them a call in the morning and then get on about my day."
30°C