John Mayer Joined Onstage by Questlove After Bandmates Test Positive for COVID Hours Before Show

John Mayer, who is currently on the road on his Sob Rock Tour, announced Monday that his drummer Steve Ferrone has tested positive for COVID-19.

The musician, 44, revealed the news on social media before he was scheduled to take the stage for the second of his two sold-out shows at Madison Square Garden in New York City.

"This afternoon, our drummer tested positive for COVID-19," he wrote. "Tonight's concert @TheGarden will go on as scheduled, with a very special presentation. We all wish him a speedy recovery and look forward to seeing you all at the show."

Once the concert began, Mayer revealed background vocalist Carlos Ricketts was also down with the virus. Mayer performed the majority of the concert acoustic, before surprising the audience with an appearance from Questlove, who took over on the drums.

"Tonight's show was special in ways that I'm still processing. We send our love to @steve_ferrone and @made4good in hopes they traipse through Covid and return to the stage quickly. My boundless appreciation goes out to the legendary @questlove, who stepped in on an hour's notice to help end the show on such a powerful and definitive note."

"The brilliant musicians in this band stepped up in ways that I will never forget, and will bond us forever," Mayer captioned a series of photos from the night on Instagram.

"Most importantly, I thank everyone in attendance whose enthusiasm and energy in the face of some disappointing news lifted us all to something far greater than I could have ever expected. It's the honor of my life to share these nights of music with you. The next couple of tour stops will feature this format (minus the very otherwise-engaged @questlove) and I will devote every moment to making sure we bring you the best show we can. Thank you, NYC. ♥️"

Questlove, 51, later shared his own post, writing, "Welp. I thought I was hangin with the crew tonight. the plan was seeing a kick ass band at @thegarden —-I came home from LA early to do @fallontonight then me & my guys @bsherman2222@sugasteve (from @qls) & @rayangry headed to see @johnmayer & @greg_phillinganes_live & @pino_palladino_official_ & @drh3 & @sharkey335@steve_ferrone & the rest of 'the avengers of music'——-I got out my show clothes all excited & then I checked my phone: 'Ferrone got covid, can you sit in?' 😬😳😧"

The Tonight Show bandleader continued, "Truth be told I coulda played the whole show. I texted Jimmy [Fallon] earlier I felt like Don Henley in 1988 when last min he played drums for @gunsnroses at the @amas (weirdest version of #Patience ever) I was anxious, amped, timorous, excited, scared & hyped!! Gotta say once onstage it was gravy. I haven't played with this combo since the @rootspicnic in nyc 2013 w D'angelo & we haven't lost a step. It was hella fun tonight!"

Questlove added, "This also marks the THIRD time a circumstance kept me from seeing my idol drum (Ferrone is literally WHY I drum—-first time Petty's unfortunate passing prevented me from seeing him drum & then I went to the 8th floor at 30rock to watch him sit in on @latenightseth & of course 3/16/22 the world shut down so that was strike two——and now this lol—-ONE OF THESE NIGHTS imma see my hero play drums 🤣🤣😂😂 Thanks Y'all."

Mayer was quick to respond, writing, "What you did was unforgettable and brilliant. Thank you for saving the day."

Mayer kicked off the tour on Feb. 17 in Albany, New York. The guitarist is traveling across the country through April.

The tour is named after his eighth studio album Sob Rock, which was released in July and later debuted at No. 1 on the Billboard Top Album Sales Chart.

Earlier this month, Mayer showed concern for a fan during his first solo show since the pandemic began. He paused mid-set to check on an audience member while performing during SiriusXM and Pandora's Small Stage Series concert at the Hollywood Palladium.

Never miss a story — sign up for PEOPLE's free weekly newsletter to get the biggest news of the week delivered to your inbox every Friday.

"Stop the show for one second. There's a medic situation right here. Stop for a second. Are they conscious? Give me a thumbs-up if they're alert. Need an AED? Well, that's not someone who's alert," the musician said after noticing someone in the crowd who appeared to be passed out. "I'm going to step off the stage for a second."

The paramedics stepped in to assist the woman before placing her in a wheelchair. Mayer returned to the stage minutes later and explained the incident to his audience.

"Anyone in the crowd who's worried — I'm told that she's up and waved goodbye, so she's OK. The system works, thank you very much," he shared.

The Grammy-winning artist proceeded to entertain his audience and expressed his gratitude to his friends and fans, including familiar faces in the entertainment industry, such as Jeff Ross, Heidi Klum and Tom Kaulitz, Vanessa Hudgens and Cole Tucker, and Olivia Culpo.

"After a couple of years, with so many changes and so many new things to watch and read and listen to and play, you still came out to see this show," he said. "That means a lot."

As information about the coronavirus pandemic rapidly changes, PEOPLE is committed to providing the most recent data in our coverage. Some of the information in this story may have changed after publication. For the latest on COVID-19, readers are encouraged to use online resources from the CDC, WHO and local public health departments. PEOPLE has partnered with GoFundMe to raise money for the COVID-19 Relief Fund, a GoFundMe.org fundraiser to support everything from frontline responders to families in need, as well as organizations helping communities. For more information or to donate, click here.