New Zealand recruits Stephen Kearney and Motu Tony are out of Hull FC's KC Stadium friendly against York City Knights on Wednesday.
The pair have picked up short-term injuries during the training camp in Spain.
It is hoped Tony will be fit to make his debut at Knowsley Road when FC take on St Helens in 10 days' time.
Winter signing Nathan Blacklock will play, while London Broncos' loan duo Iain Lane and Michael Worrincey will make their debuts.
Richard Swain is included in the 20-man squad but Paul Cooke and Richard Horne have been left out.