Mikkel Kessler, the 38-year-old former world super-middleweight titleholder, has delayed his comeback due to a tick bite.
The Danish boxer has been struck down by Lyme disease -- a bacterial infection spread to humans by infected ticks -- and has been forced to pull out of a planned ring return at the at the Messecenter in Herning, Denmark, on Nov. 11.
Four-time world champion Kessler, who has not fought since losing a rematch with England's Carl Froch in a world title unification fight in May 2013, now hopes to fight again in March.
Kessler fell ill in training camp and hospital tests revealed he has Lyme Borreliosis.
After being released from hospital, Kessler is now on antibiotics and is yet to resume training.
"I started to feel ill around 4 weeks ago," said Kessler. "I was tired, my muscles were aching and I was unable to train. At that point, I still had no idea what was causing it. I had blood tests, which showed nothing, and it wasn't until I had a spinal fluid test that the doctors were able to identify the problem.
"I'm not sure exactly when or where I was bitten by the tick, but I'm just thankful the bacteria was caught early and hopefully there will be no long lasting effects.
"Obviously, I'm disappointed to have to delay my comeback. I want to thank my fans for their support and patience. I hope to be ready to return to the ring early next year."
Kessler beat Froch in 2010 after defeats to American Andre Ward and Wales' Joe Calzaghe.
"I've had fighters suffering from many different injuries and illnesses in the past but this is a first for me," said Kessler's long-term promoter Kalle Sauerland.