The 23-year-old football star apparently ran into Disick at a Bootsy Bellows party at the annual desert music festival, and reportedly appeared drunk, according to Page Six.
"He arrived wasted, partied wasted and stayed wasted," a source told Page Six of the former NFL star. "Scott Disick was hanging with Manziel and Kendall and Kylie Jenner. It appeared as if [Manziel] crashed their table.
"He poured himself drinks from their bottles. He was stumbling as Post Malone hit the stage … He was dancing and sweaty."
A source confirmed to PEOPLE that Manziel was "being messy" at the Bootsy Bellows party. However other sources tell PEOPLE that Manziel did not appear to be out of control at other parties at the annual music festival.
Manziel's lawyer could be reached for comment.
This isn't the first time Manziel has hung out with Kourtney Kardashian's ex.
The two were spotted out in Las Vegas last month for a night out at 1 OAK nightclub. The two also hung out with club owner Eli Pacino at the hot spot and Disick posted an Instagram photo of himself and Manziel, declaring the outing a "Boys night."
Manziel was also seen at the Coachella festival playing in a ball pit. He even posed for a photo with rapper Drake's dad, Dennis, at the event.
"These two guys right here. family," Dennis captioned an Instagram photo of himself alongside Manziel and Drake's cousin, Ryan Silverstein, .
The Coachella outing comes just days after Manziel's agent, Drew Rosenhaus, told ESPN's Adam Schefter that he would drop the 23-year-old as a client if he didn't turn from his partying ways and seek help.
"I have terminated the standard representation with Johnny Manziel in the hopes of helping him get the treatment I believe he needs," Rosenhaus said.
"I have informed him that if he takes the immediate steps I have outlined for him that I will rescind the termination and continue to represent him."
Drew Rosenhaus has never in 27 years as #NFL agent fired a player as client. Johnny Manziel has 5 days to avoid being the first— Ed Werder (@Edwerderespn) April 13, 2016
Rosenhaus added: "Otherwise the termination will become permanent. There is a five-day window for me to rescind the termination. I'm hoping he takes the necessary steps to get his life back on track."
That termination allegedly became permanent on Tuesday, with ESPN reporting that Rosenhaus had ended his relationship with he football star. Rosenhaus did not respond to PEOPLE for comment.
This isn't the first time this year that Manziel has run into trouble with his agent. In February, his then-agent Erik Burkhardt announced in a statement that he was cutting ties with the now-former quarterback, ESPN reports.
JFF staying out of trouble pic.twitter.com/K3FijT32BY— Barstool Sports (@barstoolsports) April 17, 2016
"Though I will remain a friend and Johnny supporter, and he knows I have worked tirelessly to arrange a number of professional options for him to continue to pursue, it has become painfully obvious that his future rests solely in his own hands," Burkhardt said.
The news came just one week after Manziel allegedly hit his ex-girlfriend Colleen Crowley during an argument at a Dallas, Texas, hotel, according to police documents obtained by PEOPLE.
Crowley told authorities that the former NFL star hit her so hard she briefly lost her hearing, according to an affidavit obtained by PEOPLE.
Crowley claimed that Manziel grabbed her by her hair and threw her into his car.
"I was crying and telling him 'I hate you! Just leave me alone! I hate you!' she recalled. "[He] then told me he was going to drop me off, take my car and go kill himself."
Earlier this month, a Dallas grand jury, who were expected to hear the domestic violence case, ended its term without doing so, KTVT reports.
A Dallas County District Attorney's Office spokesperson told the station that the case was "rescheduled" and will "probably" be heard by a new grand jury.
In January 2015, Manziel spent more than two months at a rehab treatment center, his attorney told ESPN then. The attorney did not reveal details of Manziel's treatment, but the facility specializes in drug and alcohol rehabilitation.
By the end of April 2015, Manziel was back to training with the Browns.
Manziel was drafted by the Browns – in the first round – in 2014 and dropped by the team last month, according to CBS Sports.
Reporting by MELODY CHIU