The reigning Premier League champions begin their quest for a third title in a row when they take on West Ham on Saturday.
Nemanja Matic has immediately improved United's midfield.
Mourinho has made three signings so far this summer.
Newcastle was promoted to the Premier League on Monday.
Pérez has not pinned down a starting place at Arsenal.
West Ham is looking to move into the top half of the Premier League table.
West Ham thumped by Manchester City, 5-0, at the London stadium.
Guardiola's team faces a fight to make the top four.
Mourinho's United has drawn level on points with Tottenham.
United has now gone 11 Premier League games unbeaten.
United toiled for most of the game in east London.
Pogba has begun to dominate recent games.
Ibrahimovic had a "fantastic year."
Tevez enjoyed a productive period in the English Premier League.
Rashford and Martial are struggling for game time at Old Trafford.
Sanchez scored three and set a goal up for Mesut Ozil.
Arsenal kept pace with Premier League leader Chelsea.
United is in the semi-final of the EFL Cup.
The Gunners crashed out of the EFL Cup.
Mourinho was sent to the stands during Sunday's draw with West Ham.
Harry Kane wants to stay in London.
Payet has been linked with a move away from West Ham.