Slovakian shooter Danka Bartekova will deputize for the absent Tony Estanguet as the International Olympic Committee (IOC) Athletes' Commission representative at a World Anti-Doping Agency (WADA) Executive Committee meeting in Seoul.
Three of the four IOC Athletes' Commission representatives on the WADA Foundation Board are unable to attend their meeting scheduled for the following day.
As well as Estanguet, who is preoccupied by his main job as chairman of the Organizing Committee for Paris 2024, United States' IOC Athletes' Commission chair Angela Ruggiero and Zimbabwean member Kirsty Coventry will also be absent.
South Korea's Ryu Seung-min and Bermuda's World Olympians Association representative Patrick Singleton will join Bartekova in deputizing on the Foundation Board.
Pengilly, as the sole permanent representative present, could have been expected to have also sat on the Executive Committee.
But the IOC confirmed to insidethegames today that this was not the case.
The WADA meetings in the South Korean capital will discuss matters including whether to readmit the Russian Anti-Doping Agency following their suspension after the first of two explosive WADA-commissioned reports on doping problems in 2015.
They are also expected to study fresh evidence of possible Russian sample tampering obtained following their recent obtaining of a database of information from the Moscow Laboratory.
Pengilly was the only IOC member to vote against the body's ruling Executive Board in a motion of confidence into their response to Russian doping last year after the publication of the second report, written by Canadian lawyer Richard McLaren, into evidence of institutional doping at Sochi 2014.
The IOC Athletes' Commission is meant to represent the interests of athletes, however, rather than those of the IOC.
Twelve members sit on the WADA Executive Committee.
WADA President Sir Craig Reedie and vice-president Linda Hofstad Helleland, the Norwegian Minister of Culture, will be joined by four other representatives of the Olympic Movement.
These should be: Czech Olympic Committee President Jiri Kejval, Switzerland's International Basketball Federation secretary general and Global Association of Summer Olympic International Federations, Patrick Baumann, Turkey's World Archery President and IOC vice-president Uğur Erdener, and Italy's Association of Summer Olympic International Federations President, Francesco Ricci Bitti.
The panel is completed by five representatives from public authorities.
These should be: Australian Minister for Sport, Greg Hunt, African Union Commissioner for Social Affairs, Amira El-Fadil, Poland's Minister of Sport and Tourism, Witold Bańka, Dominican Republic's American Council for Sport President Marcos Dias and Japan's State Minister of Education, Culture, Sports, Science and Technology, Toshiei Mizuochi.