Siegfried & Roy‘s final shocking performance.

Friends of illusionists Siegfried & Roy fear that doing one final show could kill Roy Horn, who has never fully recovered from being mauled onstage by a tiger five years ago.

Despite the risks, insiders say gutsy Roy insists the show must go on – and Siegfried vows they’ll perform as promised.

The Las Vegas legends are already rehearsing for their farewell performance on Feb. 28 at the Bellagio hotel and casino, which will be filmed for a prime-time Alphabet Net special.

"We never got to say a proper goodbye," Roy said recently during a tour of Sin City’s new Lou Ruvo Brain Institute. "This will be our final bow, and it will never be repeated."

Siegfried added: "It has given Roy a whole new lease on life. We are both incredibly excited about doing this one last time."

The master magicians performed some 5,750 shows together before a male white tiger named Montecore seriously injured Roy during their act on Oct. 3, 2003 – his 59th birthday.

The beloved performer suffered severe blood loss from the attack, and The ENQUIRER reported that Roy’s heart stopped more than once while fighting for his life during surgery at University Medical Center in Las Vegas.

Roy’s rehabilitation took years, and friends say he’s never fully recovered. They fear the final show is a foolhardy exercise that could cost him his life.

"Roy still suffers from partial paralysis on the left side of his body, and he can’t move his left arm," said a longtime friend.  "He just shuffles along, and it’s clear that he can’t possibly move quickly enough to attempt most of the illusions that he used to do. Roy has got all the guts in the world to try to perform one last time. But, frankly, he’s in no shape to even attempt it."

"The cats sense weakness. If one lunged at Roy, he’d be dead meat!"

For all the details pick up the ENQUIRER!