Hornets pair Almen Abdi and Daniel Pudil have completed their moves to Hillsborough.
Mauricio Pochettino worked at Southampton before moving to Premier League rivals Tottenham Hotspur.
Rangers reportedly won't be bringing striker Joe Garner to Ibrox this summer.
The full-back came in for stern criticism for his poor performances last season.
Tottenham take on Atletico Madrid in another International Champions Cup match in Australia.
The Northern Ireland international had time off in the summer after Euro 2016.
West Ham United lost 2-1 to NK Domzale on Thursday evening.
Glasgow Rangers boss Mark Warburton has brought nine players to Ibrox this summer, and his first said he was shocked.
West Ham United are reportedly closing in on a deal for Andre Ayew.
The Gers boss still intends to strengthen his squad.