Jason Day revealed how a talking to from his wife helped him overcome a back injury to challenge for a second major title in the 83rd Masters.

Day was close to pulling out during his opening round on Thursday after re-injuring his troublesome back by bending down to kiss his daughter before the start of play.

The Australian needed treatment on the course and managed to complete an opening 70 before adding a second round of 67 to finish alongside Francesco Molinari and Brooks Koepka on seven under par.

"This morning I woke up and I was disappointed because I thought my back was going to be a lot better than what it was, but obviously we worked on it last night so things are going to be sore," Day said.

"But I was kind of moping a little bit in the bath and my wife Ellie said 'It's the Masters, you need to suck it up'. So I can't complain about it too much because she's birthed three children and I haven't.

"She's a lot stronger as a person than me with regards to pain and I just hit a little white golf ball around a course. I've got to listen to that. She's in my corner. We got some good work in this morning with regards to the back, and things felt much better."

Day, who won the US PGA in 2015, had to withdraw from the Arnold Palmer Invitational after just six holes of his opening round and revealed the bizarre lengths he goes to in an attempt to manage his situation.

"This is going to sound really weird (but) I have to get my ribcage back in position," the former world number one said.

"I blow into balloons in certain positions to try and get my ribcage down and I've got these other exercises that are trying to get space in the joint with regards to my hips and my back and my shoulders.

"Sometimes I wake up and I feel like I'm 50, sometimes I wake up and I feel like I'm 70, and sometimes I wake up and feel like I'm 18 again. It just comes and goes, and that's just how it is."