A.J. McLean has vowed to help and support his troubled friend Aaron Carter.
The Backstreet Boys singer - who has been in rehab three times to be treated for substance abuse issues - wants to reach out to his pal in order to help him get back on the right path after the 'I Want Candy' singer recently checked into a treatment facility to "work on his wellness".
Speaking to gossip website TMZ, A.J. said: "I'm gonna call Aaron. I'm just gonna tell him I've been through this, I realise that you're in denial. I realise there's a lot shame involved, but it takes the bigger man to admit when you're wrong.
"It takes someone who's willing to get help, to listen to others who care about you and have been down the same road. Three times I've been to rehab, and I've come out on the other end. Jails and institutions, or death - that's your only three options if you don't get it right."
Aaron and his older brother, Nick Carter, have a notoriously fractured relationship, and the 'I Want It That Way' singer can understand why his 37-year-old bandmate has grown "frustrated" with his younger sibling.
He added: "I've been down that road. I've come out the other end, I'm sober today, but at the same time, it's a lot of work. I am definitely worried about him, I love him like he's my little brother.
"I think Nick's at a point where he's really frustrated, he doesn't know what to do, they've tried a lot of things."
Hours after Aaron's representative confirmed he was checking into a treatment facility last week, the 29-year-old singer revealed before quitting social media that he no longer has any contact with his family and explained that his "stressors haven't subsided" with them.
He wrote: "FYI. MY FAMILY has nothing to do with this. I've actually had to cut them all off unfortunately and it's gonna stay that way.
"We can talk about this when I'm done taking care of myself. that goes to everyone especially the medias. I'm gonna have a lot to say. Thanks
"I am strong, that's why I made this decision. No one could've forced me. None of you even know my reasons for this. It's called stress."