Clemons, 69, who lives in Florida, fell ill over the weekend, according to sources on gossip and fan websites and Rolling Stone magazine. But representatives for the horn player known as "Big Man" had declined to disclose any information about his condition.

Springsteen, in a statement issued through his publicist Marilyn Laverty, said, "While all initial signs are encouraging, Clarence will need much care and support to achieve his potential once again.

"He has his wonderfully supportive wife, Victoria, excellent doctors and health care professionals, and is surrounded by friends and family.

"I thank you all for your prayers and positive energy and concern. This is a time for us all to share in a hopeful spirit that can ultimately inspire Clarence to greater heights."

Clemons underwent double knee-replacement surgery in 2008 and walked for the first time in three months when Springsteen and the E Street Band played the Super Bowl in 2009.

Springsteen's statement said fans could send email messages to Clemons at notestoclarence@clarenceclemons.com.

Clemons started playing with Springsteen in 1971 as a charter member of his E Street Band. His gritty, haunting solos power such hits as "Born to Run," "Jungleland," "Prove It All Night," "Tenth Avenue Freeze Out" and "Badlands."

Away from the E Street Band, Clemons enjoyed a hit single in 1985 with "You're a Friend of Mine," a duet with Jackson Browne. He has dabbled in acting and worked with other artists including Ringo Starr, Aretha Franklin and Lady Gaga.

Copyright Reuters, 2011