He may cover 5km in a game but it is split into 2 halves and there are a number of in game breaks. There is no reason to continuously run that entire distance in one big hit if your trying for higher levels of specificity (which I don’t necessarily believe you should do)
Sports where athletes run 25km per game dont have them covering those distances in training, they are usually far closer to 3km and many times not at all as the actual game and other training keeps them conditioned.
Basically, the OP shoukd be as conditioned as he needs to be to finish the game off, not to run 10km trials.
I agree. I just feel that 5k 2x a week is a good base and maintenence level. It represents a 90% reduction in running volume from what he was doing in any case, and that means a 90% reduction in recovery costs that wil be used to recover for weight training. Also one has to remember that there are still a LOT of rugby coaches that love to run their athletes to death in practice, so maintaining some skill is useful to avoid the shock of training camp being as rough as it might otherwise be.
In general I believe that if one already has a certain level of skill in a task (be it running, lifting, shooting or whatever) then it is much better to maintain a certain relaxed level of training in that task than drop it almost entirely.
I agree that agility drills and sprints are valuable.