The Brandon Aiyuk divorce from the San Francisco 49ers is getting ugly.

Mere days after it was reported that the Niners would void the two-time 1,000-plus-yard receiver’s guarantees for 2026, insider Jeremy Fowler reported the issue stemmed from Aiyuk’s unwillingness to show up for rehabilitation appointments for his surgically repaired knee.

Aiyuk has not played since Week 7 of 2024 against the Kansas City Chiefs when he tore his ACL and MCL in the Niners’ loss.

His relationship with 49ers brass became strained earlier last season during a contract dispute, where Aiyuk requested a trade before ultimately signing a four-year, $120 million contract, in which 2025 is the first year.

Brandon Aiyuk Reportedly Didn’t Show Up For Rehabilitation

Aiyuk’s return to the field has been delayed — the 49ers have not yet opened his 21-day window to return from the PUP list — which has frustrated fans. The Niners are hanging on offensively — they won while scoring just 20 points on Monday night against the Carolina Panthers — while they await the No. 1 receiver’s return from the knee injury sustained almost 14 months ago.

But the news that Aiyuk’s guarantees were being voided sent shockwaves across the NFL, and Fowler’s intel indicates they involve the 2020 first-round pick’s unwillingness to participate in rehab for his knee injury over the summer.

“A few people I’ve checked with believe an issue was Aiyuk’s failure to show up for rehab appointments during the offseason,” Fowler reported Wednesday. “Either he didn’t trust the trainers or didn’t want to show up. Either way, an unwillingness to properly rehab a significant knee injury as the team sees fit is typically easy grounds for a guarantee void.”

Brandon Aiyuk Is Unlikely To Be With The 49ers Beyond This Season

The NFLPA offered to grieve Aiyuk’s voided guarantees — especially his nearly $25 million option bonus, which is now up in the air. But Aiyuk informed the union not to push back, and he may have played his final snap with the 49ers, according to The Athletic.

“Aiyuk, sources say, has failed to attend meetings and declined to participate in other team activities in recent months, and the 49ers have grown increasingly frustrated with the receiver’s lack of communication,” Dianna Russini reported earlier this week. “The 49ers, sources say, responded by voiding the guaranteed money in Aiyuk’s contract for 2026, asserting that the absences amounted to a failure to fulfill his contractual obligations.

“Aiyuk, according to multiple league sources, told NFL Players Association representatives that he did not want to fight the move via an official grievance. That would clear the way for his expected release at season’s end.”

Aiyuk is still under contract with the 49ers, who may want to trade the disgruntled wideout to recoup a draft pick or two for him this offseason. But if they don’t, he will be released by the team — likely after June 1, since the Niners can then avoid a nearly $30 dead-cap hit by cutting him then.

Or Aiyuk could work with the 49ers to restructure his deal so they won’t be in cap hell and so he can join a team right when the 2026 league year opens in March.

“A few teams I spoke to believe Aiyuk is slightly more tradeable with the voided guarantees,” Fowler reporterd. “Though with the option money still technically on the books, reworking his deal altogether would be the preferred method.

“Aiyuk might not want that. Getting released and hitting free agency in March would be the cleanest path for him — and he would have suitors. He’s only 27 and had 1,342 yards in 2023.”