The 33-year-old reality star was formerly married to the retired basketball player from 2009 until their divorce was finalised last year, and although Lamar sparked concern for his health recently when he collapsed in a Los Angeles nightclub, sources say Khloe is wishing him well from afar.
An insider told Us Weekly magazine: ''Khloe and Lamar have no communication. She's aware that he's off the wagon and she has known it for a long time, so it's not a surprise to her. She wishes for the best for him.''
The 'Keeping Up with the Kardashians' star's well wishes come after Lamar, 38, was found slumped in a chair in his VIP booth at Bootsy Bellows nightclub, and was seen in a video clip to be helped up by other patrons.
Sources said after the event that the star is coming dangerously close to another downward spiral, after he was previously found almost dead following an overdose at the Love Ranch brothel in Las Vegas, Nevada in 2015.
One insider said: ''Lamar is spiralling again. He's out of control. He was better this spring but things got worse over the summer and everyone is worried things are going to get even worse and they're scared for him.''
The sports star's previous near-death experience in October 2015 came after Khloe - who is now in a relationship with Tristan Thompson - filed for divorce in 2013, and had papers signed by both parties in July 2015.
Following Lamar's health scare - which saw him in a coma for four days - Khloe withdrew her divorce petition so she could make medical decisions on his behalf whilst he recovered, and their divorce was later finalised in December 2016.
Take a look back at October's inaugural event.
The film is expected to continue without Mendes' involvement.