Rugby players on mature sort of deal (7)
I believe the answer is:
package
'sort of deal' is the definition.
(package deal)
'rugby players on mature' is the wordplay.
'rugby players' becomes 'pack' (a rugby scrum is formed by two packs of players).
'on' means one lot of letters go next to another.
'mature' becomes 'age' ('age' can be a synonym of 'mature').
'pack'+'age'='PACKAGE'
(Other definitions for package that I've seen before include "Put into a box/wrapping" , "Wrapped consignment" , "Parcel or bundle as for posting" , "Whole" , "tour" .)