Ross – who was West Ham’s top scorer in the WSL last season – will be joining Manchester United, while Percival is going to Tottenham Hotspur.
Ross played 75 minutes for Scotland during the World Cup – in a 2-1 loss against Scotland, as they narrowly missed out on a place in the knockout stages.
Percival played every minute of New Zealand’s tournament, though they finished bottom of their group, having lost all three of their games after conceding late goals against Netherlands and Cameroon.
This development leaves West Ham in a worrying position, as the squad is currently only made up of 14 players – with the club having not made a single signing yet this transfer window.
With the team going back for pre-season next week and the season starting against reigning champions Arsenal on the weekend of the 7th-8th September, there is a need for new recruits to start coming in soon, rather than more outgoings.
Having reached the FA Cup final in their maiden season as a professional club, it will have been presumed that the Hammers would be doing all they can to progress as a club.
While there is still time to bring players in, it is getting to the stage where action is needed urgently.