LVG was Netherland's manager at that time and was confirmed as joining Utd before the World Cup iirc. I just looked at his stats with LVG in the following season:
https://www.transfermarkt.co.uk/robin-van-persie/leistungsdaten/spieler/4380/plus/0?saison=2014
I misremembered the details of RVP being dropped for Rooney as he seemed to have played every league game when available. I think what I meant to say was that RVP was unceremoniously let go in that summer of 2014-15 because 'he was done physically, went off a cliff' and we kept Rooney instead, who I thought was way worse performing. I think the fact that LVG had a pretty successful run during the 2014 World Cup with RVP being one of his main men and then kind of subsequently dropped for Rooney because there was only room for one (faded) star striker the next season after was my gripe.