Arsenal gave one of their worst performances in recent memory.
Lemar, 21, has three years left on his Monaco contract.
Oxlade-Chamberlain is in his final year of contract at Arsenal and has not yet signed a new deal.
Liverpool outclassed Arsenal 4-0 at Anfield on Sunday (27 August).
Reds deservedly securely three points against a woeful Arsenal.
Gunners boss does not rule out the possibility of injury-plagued midfielder agreeing an extension.
Arsenal star's contract expires in the summer of 2018.
The 22-year-old leaves north London after six years on the Gunners' books.
Perez made just two appearances in the Premier League for Arsenal last season.
Gunners boss admits players could both leave and arrive in final week of the transfer window.
Reports suggest that midfielder will hold further talks with the Gunners soon as transfer deadline approaches.
Wilshere was sent off while playing for Arsenal's Under-23 team against Manchester City U-23.
Mourgos joined Arsenal in 2014 but failed to break into the first-team.
Gunners boss laments the huge asking prices from clubs around Europe for their star players.
Sanogo, Szczesny and Gabriel are the three first-team players to have left on permanent deals thus far.
Wilshere was sent off along with Manchester City's Tyreke Wilson.
Wenger has stated his desire to trim the first-team squad due to the high numbers.
Sanchez has missed Arsenal's opening 2 games of the season due to injury.
Pep Guardiola will pursue Sanchez until the transfer window closes, according to reports.
Perez made only 2 league starts for Arsenal last season.
The trio were heavily involved during Arsenal's pre-season tour of Australia and China.
Sanchez missed the opening Premier League game of the season due to an abdominal strain.