Southern rockers Lynyrd Skynyrd [ tickets ], who last week canceled several co-headlining dates with Sammy Hagar [ tickets ] due to guitarist Gary Rossington's illness, have now scrapped the remainder of the joint outing.

Last Friday (7/29), Skynyrd announced that it was pulling out of six shows so that Rossington--who underwent heart surgery earlier this year--could recover from "medical fatigue." Doctors have since determined that his condition is more serious.

"Upon further medical testing and analysis," reads a press release that the band issued on Tuesday (8/5), "Dr. Matthew W. Gwynn at Atlanta Neurology determined that Rossington suffered a mild seizure and he's now under the doctor's care."

The release goes on to say that Rossington was released from the hospital on Monday (8/4) and "will need at least three weeks of house rest prior to touring."

The band plans to kick off its own headlining tour on Aug. 23 (see dates below) in support of its May 20 release, "Vicious Cycle." The album, which is the group's first new studio set in four years, was originally due out on May 6, but the group postponed the release following Rossington's quintuple-bypass surgery.

Skynyrd frontman Johnny Van Zant said in a statement that he and his band "encourage all of the fans to head out and see Sammy carry the torch. Sammy's an excellent artist! Great music and hot babes. What more could you ask for?"

Hagar and his band, the Waboritas, will resume the tour on their own starting Tuesday (8/6) in Corpus Christi, TX, but the tour's Aug. 10 and Aug. 12 stops in San Antonio and Denver, respectively, have been canceled outright. Refunds are available at the point of purchase.

"Sammy & the Wabo's Live Hallelujah," Hagar's new album, landed in stores on May 20. He recorded the set during last summer's co-headlining run fellow ex-Van Halen frontman David Lee Roth.