Rules are bit ambiguous
16.5.2 For an absent Rider with (a) an assessed MA, or ( has been approved in a team’s declared line-up at the start of the season, a 28-day Facility may be granted at MC’s discretion
16.5.3 No facility is permitted to replace a Rider, who although included in a Re-declaration has not made an appearance for that Team since being re-declared.
My interpretation is that Wolves can use either a Guest or R/R if Craig Cook is available I'd go with the Guest option but it will probably R/R, but I'm only a supporter so what do I know.