"Raymond Faitala-Mariner will come into the side and start and probably Sione Lousi will be added to the bench."
McFadden acknowledged the visitors have their own staffing issues, with fullback Billy Slater out for the season after shoulder surgery and two other key personnel backing up post-Origin.
After consolidating seventh position with back-to-back wins over the Gold Coast and Canberra he stressed the need for his side to maintain their standards and consistency.
"With Cooper Cronk and Cameron Smith backing up from Origin and missing Billy there is maybe a better opportunity," he said.
"The ladder is still very congested and these points count, especially for us, because we're playing teams that are around about the same position.
"It's very important, particularly against Melbourne this week, because we can certainly surge up or down the ladder depending on results."
The Warriors' recent improved showings were not the result of any great changes to their playing style or preparation, and McFadden believes his players are simply feeling more confident in their roles after seeing the benefits of sticking to and executing their game plan effectively.
"We know we've put ourselves in a position to do something so we've just got to keep working hard.
"We've just got to keep focusing on performance but there's no doubt that our expectations are that we're in the finals at the end of the year."