Mikkel Kessler's boxing comeback has been delayed after the former world super middleweight champion contracted Lyme disease.
Kessler had been expected to return to the ring next month but will now be unable to end his absence of over four years until March 2018.
The 38-year-old has been released from hospital and is completing a course of antibiotics after being struck down by the illness.
"I started to feel ill around four weeks ago. I was tired, my muscles were aching and I was unable to train," Kessler said.
"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, and I promise to repay their support with a great victory!"
"I've had fighters suffering from many different injuries and illnesses in the past but this is a first for me," said promoter Kalle Sauerland.
"I know Mikkel is bitterly disappointed, but his health must come first. We are now set for March and will announce venue and opponent in the coming weeks. It will take more than a tick to stop The Viking Warrior!"
Kessler holds a 46-3 record, his last fight a loss to Carl Froch in a rematch in London in 2013.
|Cahill still has something to offer Australia - Bosnich|
|Fear has discouraged Danes from travelling to Russia, says Sorensen|
|Reds rally to complete four-game sweep of Cubs|
|Arzani ready for Socceroos start against Peru – Skoko|
|Braves place closer Vizcaino on DL with right shoulder inflammation|
|West Indies hold slight edge against Sri Lanka|
|Don´t touch my Grizou – Pogba defends France team-mate|
|Yankees catcher Sanchez likely heading to DL|
|Messi is frustrated and hungry – Mascherano|
|Nainggolan the ´ninja´ Inter were missing, says Spalletti|
|Anthony fires back at Thunder fans unhappy he´s staying|
|MLS Review: New York City edge Toronto in Torrent´s first game|
|Watson shoots 63 to win Travelers for third victory of season|
|Iran contest not all about Ronaldo, insists Santos|
|Truex´s team use tricky strategy to win at Sonoma|
|World Cup 2018: England at home, Brazil´s party and exploding White Nights in St Petersburg|
|Pogba reveals ´issues´ with Mourinho|
|Mascherano plays down rumours of Sampaoli bust-up|
|Sweden winger Durmaz says racist abuse ´passed limit´|
|Morgan hails ´outstanding´ Buttler century|
|Paine to discuss ODI future after England whitewash|
|Cuper unsure of Egypt future as El Hadary nears milestone|
|Koepka ´shutting down´ until Carnoustie|
|Quintero and James plot Colombia´s way through uncharted territory|
|Federer upbeat despite shock Halle defeat|
|Journalists should round on Vettel - Verrstappen|
|Poland 0 Colombia 3: Falcao´s maiden World Cup goal revitalises Pekerman´s side|
|World Cup 2018: Cossack kids, Swan Lake and the Selecao in Rostov-on-Don|
|Maria takes maiden title in Mallorca|
|Hierro: I am 100 per cent the coach of Spain|
|Busquets recognises Iniesta´s burning ambition|
|Denmark v France: Tolisso hoping for second chance|
|Eight-try Wakefield hammer sorry Widnes|
|World Cup 2018: A panda, a tapir and a nightmare for Willy in Nizhny|
|Senegal´s Wague makes African history in World Cup|
|Cilic fights back to beat Djokovic in enthralling Queen´s final|
|Neymar and Suarez among players to send Messi birthday wishes|
|Strength of Senegal and Japan´s determination could trouble England and Belgium|
|Hamilton questions Vettel punishment after Bottas´ race ´destroyed´|
|Brilliant Buttler seals whitewash in Old Trafford thriller|
|World Cup 2018: An egg-and-spoon race, vodka and the Pogbas in Kazan|
|Queiroz tells his Iran players to follow the ´three Rs´ against Ronaldo and Portugal|
|Pizzi calm over Salah threat|
|Japan 2 Senegal 2: Honda gatecrashes Cisse´s party|
|Harden should be MVP ´hands down´, says World Peace|
|Southgate optimistic over Alli recovery for Belgium decider|
|Neymar´s tears no surprise to Fagner|
|Unhappy Renard continues ref rant|
|Wallace takes BMW International title despite Olesen 61|
|Hamilton cruises back to standings summit with France win|
|In-form Kvitova defends Birmingham title|
|Southgate responds to toughest England week in record-breaking style|
|Uruguay not thinking about Portugal or Spain, insists Cavani|
|Coric stuns Federer to claim title in Halle|
|England 6 Panama 1: Kane hat-trick sees Southgate´s side sail through|
|Australia v Peru: Juric keeping the faith as Socceroos chase unlikely last-16 spot|
|England surpass class of 1966 in Panama rout|
|Nigeria v Argentina: All eyes on Messi to rescue final World Cup chance|
|NSW seal Origin series with comeback win|
|World Cup 2018: Stalin´s bunker, a space museum and Serbian specials in Samara|
|Croatia looking out for number one - Lovren|
|Heritage at back of Australian minds ahead of potential Croatia encounter|
|It may be my last World Cup - ´Realistic´ Pogba determined to reign in Russia|
|Lionel Messi´s birthday: What might the Barcelona star wish for?|
|Russia readying Dzagoev for last-16 clash|
|Germany apologised for reaction aimed at Sweden bench|
|Picture this! Sterling starts for England against Panama|
|World Cup 2018: A Russian romp, Maradona and the party in Moscow|
|Happy birthday, Lionel Messi! 10 of the Argentina star´s best goals|
|Modric worthy of Ballon d´Or, says Lovren|