Australia has been on the road since the beginning of the home summer in November.
After hosting Pakistan and New Zealand for Test matches, Australia travelled to India for three ODIs in January and then faced South Africa in another away limited-overs series.
Read Also: "Proud of the boys", De Kock jubilant as Proteas script 3-0 series whitewash
The never-ending schedule will now see Langer's wards take on the Black Caps at home in three ODIs and then fly across the Tasman sea for a three-match T20I series just before, with the exception of Mitchell Starc, they all join their respective IPL franchises.
"The truth is we've got some weary boys at the moment, particularly our senior players," ESPNcricinfo quoted Langer as saying at the end of the 3-0 ODI series loss to Proteas.
"They play so much cricket. When you think about what they've done since we started the World Cup, they went straight from the IPL, which is almost a year ago, straight to the World Cup, straight to the Ashes, straight to what has been a golden summer for us until probably these last three one-dayers. We've got some weary boys. We know we've got six more games to play and then they've got to go again."
The first ODI against New Zealand begins in Sydney on March 13 followed by another game at SCG on March 15 and the final one-dayer in Hobart on March 20.
"The challenge is (identifying) which series is less important," Langer said. "Because South Africa here is a really important series. Coming back after [what happened] two years ago, that was a really important series for us."
"And I've got to say it's been a great series or a great time here both in the hospitality, the way we've been treated, the way everyone has looked after us has been brilliant. So that's an important series."
"Then we play New Zealand who made the World Cup final. They're a very good team and great rivals so that becomes a pretty important series."
The T20I series in New Zealand in flat batting conditions and small boundary dimensions is also considered crucial to Australia's T20 World Cup preparations.
"The T20s we're pushing for the World Cup, so that's a pretty important series," Langer said. "So there's not too many now in international cricket where you think maybe we can take the foot off it, because as soon as you do get beaten like we have today and it's a terrible feeling being beaten."
"The truth is we've got a bit of an eye to the T20 World Cup. Obviously, we've got two [T20 World Cups] in a row. We've still got another four years until the next one-day World Cup."
(Inputs from ESPNcricinfo)