When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. A cancer diagnosis is so difficult. It felt very devastating when Dave called. Dave and [his wife] Melissa called and let us know personally before it went out to the press.

The "Full House" alum revealed Thursday that he wasn't able to shave his head because he's filming a new project soon — and said the criticism "really hurt me."

Actor Dave Coulier is speaking out after his longtime friend and former co-star John Stamos received backlash for wearing a bald cap while shaving Coulier’s head. This month, the “Full House” stars got together to share a few laughs after Coulier publicly revealed his Stage 3 non-Hodgkin lymphoma diagnosis.

John Stamos shared a post in solidarity with former Full House co-star Dave Coulier — but fans weren't feeling the love.

John Stamos says he was caught off guard by the controversy his bald cap tribute to Dave Coulier has caused on social media. The actor ripped critics who slammed his Instagram post featuring the former “Full House” co-stars just days after Coulier announced he’d been diagnosed with Stage 3 non-Hodgkin lymphoma.

Now, on Instagram, his “Full House” co-star John Stamos shared images of the lifelong friends together. Stamos was wearing a bald cap and shaving Coulier’s head. “Nothing like throwing on a bald cap and flexing some Photoshop skills to show some love and solidarity with my bro, Dave Coulier,” Stamos wrote.

TMZ caught up with the Full House alum, 61, and asked him about the reaction to his Nov. 18 Instagram photos with his former costar, 65. The images showed Coulier — who was recently diagnosed with stage 3 non-Hodgkin lymphoma — with a freshly shaved head. Stamos wore a bald cap in support.

I’m embarrassed for people that they waste time on this," Stamos said of the backlash. "All I was doing was cheering up a friend."

Dave Coulier and John Stamos have a long history. The two spent years filming the beloved series Full House together, but their friendship did not end there. After the 65-year-old revealed he was diagnosed with stage 3 Non-Hodgkin lymphoma,

Earlier this month, the Full House actor - known for playing Joey Gladstone on the sitcom, revealed he had been diagnosed with a "very aggressive" form of non-Hodgkin lymphoma and was undergoing chemotherapy treatments.