Price made himself unavailable for selection, Sky Sports reported. The Welshman said last week that he's trying to focus more on his health.
"My focus is there, but health-wise, I'm not in a great place at the moment. But I'm battling on, searching for some results. Hopefully, over the next weeks, they will come and put me at ease," he said at last week's Premier League of Darts night in Leeds, which ended in the first round after a 6-2 loss to compatriot Jonny Clayton.
Nick Kenny, ranked 60th, will replace Price and play alongside Clayton for last year's finalists, Wales, at the tournament in Frankfurt.
Lukes return for England
England, the Netherlands, reigning world champions Northern Ireland, and Scotland make up the top seeds and will enter the competition in the second round.
England will boast world champion Littler and former champion Humphries at the World Cup as they enter the tournament as the two highest-ranked players in the world. Behind them, Gian van Veen (#3) and Michael van Gerwen (#4) will make up the Dutch team, while the winning duo of Josh Rock (#7) and Daryl Gurney (#24) will return for Northern Ireland.
Gary Anderson (#11) and Cameron Menzies (#29) will play for Scotland, with Peter Wright outranked by Menzies and thus missing just his second World Cup of Darts since 2016.
Mickey Mansell, who's represented Northern Ireland at previous tournaments, switched eligibility to the Republic of Ireland and will represent the country with William O'Connor.
Slovenia will return for the first time since 2010, while Uganda, Trinidad & Tobago, and Mongolia will all make their World Cup of Darts debuts next month.
The World Cup of Darts will take place at Frankfurt’s Eissporthalle from 11th to 14th June.
Full World Cup of Darts line-up
Top 4 seeds
England: Luke Littler, Luke Humphries
The Netherlands: Gian van Veen, Michael van Gerwen
Northern Ireland: Josh Rock, Daryl Gurney
Scotland: Gary Anderson, Cameron Menzies
5-16 seeds
5. Germany: Martin Schindler, Ricardo Pietreczko
6. Belgium: Mike De Decker, Dimitri Van den Bergh
7. Wales: Jonny Clayton, Nick Kenny
8. Republic of Ireland: William O'Connor, Mickey Mansell
9. Poland: Krzysztof Ratajski, Sebastian Bialecki
10. Sweden: Jeffrey de Graaf, Oskar Lukasiak
11. Australia: Damon Heta, Adam Leek
12. Czech Republic: Karel Sedlacek, Adam Gawlas
13. Austria: Mensur Suljovic, Rusty-Jake Rodriguez
14. Latvia: Madars Razma, Valters Melderis
15. Croatia: Boris Krcmar, Pero Ljubic
16. Finland: Jani Haavisto, Jonas Masalin
Unseeded teams
Canada: Jim Long, David Cameron
China: Qingyu Zhan, Xiaochen Zong
Denmark: Andreas Toft Jorgensen, Jonas Graversen
France: Thibault Tricole, Nicolas Thuillier
Hong Kong: Man Lok Leung, Lok Yin Lee
Hungary: Patrik Kovacs, Pal Szekely
India: Nitin Kumar, Ankit Goenka
Italy: Michele Turetta, Riccardo Castelli
Japan: Motomu Sakai, Haruki Muramatsu
Lithuania: Darius Labanauskas, Mindaugas Barauskas
Mongolia: Altantulkhuur Myagmarsuren, Ganzorig Lkhagvasuren
New Zealand: Jonny Tata, Ben Robb
Norway: Cor Dekker, Kent Sivertsen
Philippines: Alexis Toylo, Paolo Nebrida
Portugal: Luis Camacho, Jose de Sousa
Singapore: Paul Lim, Phuay Wey Tan
Slovenia: Benjamin Pratnemer, Stefano Bozicek
South Africa: Graham Filby, Devon Petersen
Spain: Cristo Reyes, Jose Justicia
Switzerland: Stefan Bellmont, Marcel Walpen
Thailand: Sarayut Ouamumpa, Sowaris Rodman
Trinidad and Tobago: Joshua Balfour, James Walklin
Uganda: Patrick Ocheng, Juma Said
USA: Adam Sevada, Stowe Buntz