AUSTRALIAN signings Matt King and Michael Monaghan are both doubtful for Wolves' clash with Hull Kingston Rovers at Craven Park on Sunday.

King, who left the field with a calf tear during Wolves' 30-22 defeat at St Helens, is spending the week in a hyperbaric chamber in an attempt to be fit for round three of engage Super League XIII.

King will be joined in the chamber by Monaghan who is also rated as doubtful with a hamstring injury.