The former NBA star, who has been in recovery from a near-fatal overdose since October, was seen leaving a Los Angeles strip club on Monday before he was reportedly escorted off a plane en route to New York City.
“It’s really sad for Khloé to see Lamar in an unhealthy place. She cares so much about him but she can only do so much,” a source tells PEOPLE.
Another insider explains: “She’s not doing well. She is frustrated because she knows there is nothing she can do.”
On Tuesday, Kardashian, 32, took to Twitter and responded to fan comments about the incident, though she did not directly mention Odom’s name. That same day, the reality star tweeted a sad face emoji.
Odom’s road to recovery has taken unfortunate turns as of late. Seven months after he was found unconscious at the Las Vegas brothel, the 36-year-old was spotted drinking alone at a Los Angeles mall in May. And in late March, Odom went out for drinks before attending an Easter celebration with Khloé and her family.
In May, Kardashian filed divorce papers for a second time.
• Reporting by MELODY CHIU and AILI NAHAS