Nothing in the original story suggested we're looking to replace Gutherson at fullback - just that we're chasing someone who's position (or one of them?) is fullback, and it was a courtesy to talk to Gutho first to reassure him.
Gutho is quoted as giving his blessing, so it will just be someone who might come on from 14 and provide "x factor" (which we presume is an extra attacking dimension/prong) during part of a game, which might need Gutherson to get closer to the action in another position (e.g. centre - though possibly maybe halves/dummy half?).
If everyone settles down, this is likely only a positive move - to fill our top 30 (which is still 3 short) and use $500K of our cap money wisely for the second half of the season. As Gutho seems to have said, anything that helps the club be (more) competitive in that back end of the season, the better!