"The band was en route to their hotel after a show in Boston when a pedestrian jumped in front of their tour bus, causing it to stop short," the post reads. "Nathan is being treated for broken ribs, but is doing well."
The rockers, who are hitting the road for their Mechanical Bull Tour, initially had to postpone Sunday's show in Saratoga Springs, New York.
On Monday night, the band announced Followill's injury forced them to cancel all tour dates for the next two weeks.
"Nathan is on strict doctor's orders to rest to give himself adequate time to recover before the band can pick back up on their much buzzed about Mechanical Bull Tour," the group said in a statement.
Dr. Faiz Bhora, Chief of Thoracic Surgery at Mount Sinai Roosevelt Hospital, backed that up, adding, "The process is now to rest in order for healing to take place. To avoid complications and to make a full recovery, a break from performing to Aug. 28 is necessary."
The only exception to the two-week hiatus is the band's scheduled appearance on The Tonight Show Starring Jimmy Fallon Tuesday night. For that gig, the group has enlisted Fallon's resident bandleader, Questlove, to sit in for the recovering drummer.
Earlier Tuesday, Followill released a brief video on the band's Facebook page and YouTube channel that seems to show him in significant pain while in his hospital bed.
"Thanks for all the well-wishes, and see you guys at the next show," he said, at times putting his hand on his chest.
Followill, 35, has also been Tweeting updates to concerned fans.
"Thank you for all of the get well soons. I'm a little banged up but will be back better than ever," he wrote Sunday, later sharing a photo from his hospital bed.
Saw a tweet that said I had died. Not quite, but it feels close. Who knew that you use your ribs for EVERYTHING. pic.twitter.com/qVXwzySqNb— nathan followill (@doctorfollowill) August 11, 2014
Thanks again for all of the well wishes. Best family, friends & fans in the whole wide world.— nathan followill (@doctorfollowill) August 11, 2014