The Chris Robinson Brotherhood have announced that guitarist Neal Casal will have to miss the band’s upcoming shows due to “unforeseen circumstances.” Greg Loiacono, co-founder of fellow California outfit The Mother Hips, will fill in on guitar.

“Due to unforeseen circumstances, our brother Neal Casal will not be with us for a handful of upcoming shows,” a statement from the band on social media reads. “Our great friend Greg Loiacono will be stepping in during Neal’s absence. We look forward to seeing our CRB freak family in the coming weeks!”

This Saturday, CRB’s set at Strawberry Music Festival in Tuolumne, CA, featured Barry Sless—Robinson’s bandmate in Green Leaf Ramblers—sitting in for Casal.

Although no timetable for Casal’s absence has been revealed, CRB have a packed late-summer and fall touring schedule, continuing later this week in the Southeast. See the band’s full dates here.