Khloe Kardashian posted a throwback photo of herself with younger brother Rob Kardashian indicating that he was possibly going through tough times. Rob has kept himself away from the limelight and was also not seen on family Thanksgiving.

Khloe posted an emotional message to her younger sibling.

The 31-year-old recently spoke about Rob’s relation with her and her estranged husband Lamar Odom.

"He's charming, charismatic, everything. That's what's so infuriating. I'm like, 'Where is your will to live life? Let's be around people!'" Khloe said referring to Rob’s reclusiveness in the past two years.

Rob, who gained more than 100 pounds over a year after his appearance on season 13 of "Dancing With The Stars"  in 2011, was not seen at several family events, including Kim Kardashian and Kanye West ’s wedding in 2014. Earlier this month, Khloe and Rob’s mother Kris Jenner was asked about the 28-year-old’s whereabouts on Thanksgiving.

"He lives with Khloe," Jenner reportedly said at the time. "So he was around, and then went over to a buddy’s house. He’s doing all right. You know, he’s doing his best. He’s not into being on camera as much as the rest of us. But he’s working on himself. He’s going to be okay."

It was reported in November that Rob was "disgusted" with Khloe for making him "believe" that she was getting back together with Odom. Khloe was rumored to have been dating her ex-boyfriend James Harden following a brief breakup with him after Odom’s hospitalization.

"Rob hates how she’s strung Lamar along and believes that’s why he went even further off the rails than he would have had she just set him free," a source reportedly said. "She [Khloe] led him to believe there was a chance of a reunion for so long that he put everyone on hold and had to sit there while she was wined and dined by all these other guys," the insider added.