Great Britain skipper Andy Farrell is among three or four players who could miss the Tri-Nations clash with New Zealand because of illness.
He has the same virus that robbed the team of Sean O'Loughlin and Paul Johnson for the game against Australia.
Johnson lost five kilos as a result of vomiting and diarrhoea but has been named in a 19-man squad for the game.
O'Loughlin, Iestyn Harris and Micky Higham are also in contention to play against the Kiwis in Huddersfield.
"There are three of four players who are feeling ill at the moment," said Lions coach Brian Noble, who wanted to keep the other names secret.
"It's something we are having to keep on top off because it has been ricocheting between one player and another despite us trying to keep them eating and drinking separately."
Chev Walker and Stephen Wild have been left out by Noble after featuring in the 12-8 defeat to the Kangaroos.
But winger Brian Carney is expected to be fit despite suffering a recurrence of a hamstring injury.