Following his recent collapse on-stage at the Capitol Theatre, Bobby Weir is “unable to perform in any capacity for the next several weeks,” he announced Tuesday on his Website and on the Furthur Website.The band cancelled their scheduled May 9 performance in Napa Valley, and is next slated to play the Barclays Center July 11, followed by the PNC Bank Arts Center in Holmdel, N.J. on July 12. Weir issued the following statement: “Due to unforeseen circumstances, Furthur regretfully will be unable to appear as scheduled at BottleRock Napa Valley on Thursday, May 9. Grateful Dead & Furthur Co-Founder Bob Weir, is unable to perform in any capacity for the next several weeks. “Furthur featuring Phil Lesh & Bob Weir look forward to returning to the road as scheduled on July 11 in Brooklyn for their Summer tour, which carries them through early October on the West Coast.” As first reported by ZAGSBLOG.com, Weir, 65, collapsed onstage last Thursday during the band’s ninth show in 12 nights at the Capitol Theatre. He was helped to his feet and later assisted off-stage by crew members after an incoherent performance in which he was unable to sing the lyrics to numerous songs. After the house lights came on and some fans left, bandmate Lesh told the audience Weir was dealing with the after-effects of a shoulder strain and the band then played several songs without him. The band later issued a statement saying Weir had mistakenly taken an Ambien. Weir then played with Furthur on Saturday night at Boardwalk Hall in Atlantic City.