Smith, speaking this week about the termination of his opening experiment, said Test opener Usman Khawaja and No.3 Labuschagne made it clear they preferred him to bat behind them.
"They hated me up top ... so that was a big part of it," Smith  said.
"They call it security behind them - I don't know, ask them about it. Honestly, I'm not that fussed.
"They didn't like it at all ... I can understand that."
Labuschagne said Smith's return to the position he had shone in for most of his career was not rocket science.
"One of the best players for Australia batting in the position he has had the most success in is a pretty simple fix," he said.
"Cameron Green is unavailable for the summer. There is no one batting at No.4 as we currently stand in our team. Why not have the person who has done it best for Australia batting in that position? It just makes sense.
"People want to know if there is something more (to it), but that is the reality."
Labuschagne said Smith was naturally suited to the spot.
Marnus Labuschagne (left) says he prefers Steve Smith (right) to bat at No.4 for Australia. (James Ross/AAP PHOTOS)
"I think it is his ability to read match scenarios and adapt his game to whatever the game needs," he said.
"At No.4 you have to be good at playing spin, work on when you need to push, when you need to hold and when you need to get through a tough spell. That has always been his strength."
Labuschagne said he laughed when he read that David Warner had put his hand up to come out of retirement to open, if asked.
"I don't know if he was serious or whether he was joking. It is always hard to tell," he chuckled.
"I don't know what to make of that."
Warner had also floated the possibility of Labuschagne moving up the order to fill the void, a concept the Test No.3 answered forthrightly.
"I will bat wherever they tell me to bat. Currently I would say that how I have played at No.3 has been relatively successful," he said.
"Hopefully it should be more successful, but that's where I have batted. If (selectors) think I should move and that is best for the team that is what will happen, but at this stage I think they have made it clear they are going to look down the opener route. Who that is ... is anyone's guess."
"It is a very open field."
NSW teenager Sam Konstas, Victorian opener Marcus Harris and Western Australia's suddenly out-of-form Cameron Bancroft are the three front-runners to open the batting.
