Charles Losper has withdrawn from the 2021/22 William Hill World Darts Championship, and will be replaced by Mike De Decker at Alexandra Palace.
Losper had won through the African Qualifier in October to secure a third World Championship appearance, and his first since 2009.
However, the 52-year-old from Cape Town has had to withdraw due to visa issues.
As a result, Belgium's Mike De Decker will replace Losper in the draw and now meets Darius Labanauskas on Saturday December 18, with the winner to play Dave Chisnall on Tuesday December 21.
De Decker was the highest-ranked of the "final round losers" at the recent Tour Card Holder Qualifier to be at the top of the reserve list for the World Championship.
Australia's Gordon Mathers, who is based in the UK after securing his Tour Card last January, is second on the reserve list, ahead of Peter Hudson.
Any further replacements would come in Order of Merit position from the "penultimate round losers" at the Tour Card Holder Qualifier.
William Hill World Darts Championship
Updated Schedule of Play
Wednesday December 15 (1900 GMT)
3x First Round, 1x Second Round
Ritchie Edhouse v Lihao Wen (R1)
Ricky Evans v Nitin Kumar (R1)
Adrian Lewis v Matt Campbell (R1)
Gerwyn Price v Edhouse/Wen (R2)
Thursday December 16
Afternoon Session (1230 GMT)
3x First Round, 1x Second Round
Steve Lennon v Madars Razma (R1)
Scott Mitchell v Chris Landman (R1)
Chas Barstow v John Norman Jnr (R1)
Daryl Gurney v Evans/Kumar (R2)
Evening Session (1900 GMT)
3x First Round, 1x Second Round
William O’Connor v Danny Lauby (R1)
Ryan Meikle v Fabian Schmutzler (R1)
Ron Meulenkamp v Lisa Ashton (R1)
Gary Anderson v Lewis/Campbell (R2)
Friday December 17
Afternoon Session (1230 GMT)
3x First Round, 1x Second Round
Ryan Joyce v Roman Benecky (R1)
Keane Barry v Royden Lam (R1)
Jermaine Wattimena v Boris Koltsov (R1)
Krzysztof Ratajski v Lennon/Razma (R2)
Evening Session (1900 GMT)
3x First Round, 1x Second Round
Joe Murnan v Paul Lim (R1)
William Borland v Bradley Brooks (R1)
Ross Smith v Jeff Smith (R1)
Peter Wright v Meikle/Schmutzler (R2)
Saturday December 18
Afternoon Session (1230 GMT)
3x First Round, 1x Second Round
Jamie Hughes v Raymond Smith (R1)
Callan Rydz v Yuki Yamada (R1)
Darius Labanauskas v Mike De Decker* (R1)
Ian White v Mitchell/Landman (R2)
Evening Session (1900 GMT)
3x First Round, 1x Second Round
Adam Hunt v Boris Krcmar (R1)
Ted Evetts v Jim Williams (R1)
Rowby-John Rodriguez v Nick Kenny (R1)
Michael van Gerwen v Barstow/Norman Jnr (R2)
Sunday December 19
Afternoon Session (1230 GMT)
3x First Round, 1x Second Round
Maik Kuivenhoven v Ky Smith (R1)
Jason Heaver v Juan Francisco Rodriguez (R1)
Alan Soutar v Diogo Portela (R1)
Stephen Bunting v Ross Smith/J Smith (R2)
Evening Session (1900 GMT)
3x First Round, 1x Second Round
Martijn Kleermaker v John Michael (R1)
Florian Hempel v Martin Schindler (R1)
Steve Beaton v Fallon Sherrock (R1)
Jonny Clayton v Barry/Lam (R2)
Monday December 20 (1900 GMT)
3x First Round, 1x Second Round
Luke Woodhouse v James Wilson (R1)
Rusty-Jake Rodriguez v Ben Robb (R1)
Raymond van Barneveld v Lourence Ilagan (R1)
James Wade v Kuivenhoven/K Smith (R2)
Tuesday December 21
Afternoon Session (1230 GMT)
2x First Round, 2x Second Round
Lewy Williams v Toyokazu Shibata (R1)
Jason Lowe v Daniel Larsson (R1)
Mervyn King v Joyce/Benecky (R2)
Dave Chisnall v Labanauskas/De Decker (R2)
Evening Session (1900 GMT)
4x Second Round
Vincent van der Voort v Hunt/Krcmar (R2)
Michael Smith v Meulenkamp/Ashton (R2)
Dimitri Van den Bergh v Hempel/Schindler (R2)
Devon Petersen v Hughes/Raymond Smith (R2)
Wednesday December 22
Afternoon Session (1230 GMT)
4x Second Round
Ryan Searle v Borland/Brooks (R2)
Glen Durrant v O’Connor/Lauby (R2)
Luke Humphries v Rowby-John Rodriguez/Kenny (R2)
Joe Cullen v Evetts/J Williams (R2)
Evening Session (1900 GMT)
4x Second Round
Nathan Aspinall v Murnan/Lim (R2)
Dirk van Duijvenbode v Wattimena/Koltsov (R2)
Kim Huybrechts v Beaton/Sherrock (R2)
Simon Whitlock v Kleermaker/Michael (R2)
Thursday December 23
Afternoon Session (1230 GMT)
4x Second Round
Damon Heta v Woodhouse/Wilson (R2)
Brendan Dolan v Rydz/Yamada (R2)
Mensur Suljovic v Soutar/Portela (R2)
Jose de Sousa v Lowe/Larsson (R2)
Evening Session (1900 GMT)
4x Second Round
Danny Noppert v Heaver/Juan Francisco Rodriguez (R2)
Gabriel Clemens v L Williams/Shibata (R2)
Rob Cross v Van Barneveld/Ilagan (R2)
Chris Dobey v Rusty-Jake Rodriguez/Robb (R2)
Monday December 27
Afternoon Session (1230 GMT)
3x Third Round
Evening Session (1900 GMT)
3x Third Round
Tuesday December 28
Afternoon Session (1230 GMT)
3x Third Round
Evening Session (1900 GMT)
3x Third Round
Wednesday December 29
Afternoon Session (1230 GMT)
3x Third Round
Evening Session (1900 GMT)
1x Third Round, 2x Fourth Round
Thursday December 30
Afternoon Session (1230 GMT)
3x Fourth Round
Evening Session (1900 GMT)
3x Fourth Round
Saturday January 1
Afternoon Session (1230 GMT)
2x Quarter-Finals
Evening Session (1930 GMT)
2x Quarter-Finals
Sunday January 2 (1930 GMT)
2x Semi-Finals
Monday January 3 (2000 GMT)
Final