A few days ago, it seemed as though Sanchez's long expected move to City was done and dusted, with several reports indicating that the Chilean forward had agreed personal terms with the Premier League leaders ahead of a £20 million move to the Etihad Stadium.
Sanchez, 29, did not even travel to the south coast for the lunchtime kick-off, with Gunners boss Arsene Wenger admitting he was left at home over his unresolved future.
Jose Mourinho said on Friday: "Sanchez is an Arsenal player, I don't know but probably this weekend he is going to defend Arsenal colours so I don't think it's correct to say things about Alexis Sanchez".More news: Passenger plane skids off runway and gets stuck dangling off cliff edge
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"He's being vague at the moment, the situation is not completely decided one way or the other". When at his best, the Chile global is one of the most decisive players in the world, and his pace and skill can upset any defensive line.
Discussions are believed to be underway between Klopp and Liverpool's owners, Fenway Sports Group about lodging a potential bid for Sanchez, although it will be hard for the Merseyside club to persuade the Chilean to move to Anfield due to both City and United being able to offer significantly higher wages than the Reds.
So, when it emerged Sanchez has been left out of the squad, United supporters were quick to express their excitement on Twitter... "You want to focus on the players that are on the pitch and can do well for the club". Incidentally he's won trophies with us.
It is hard to envisage Sanchez staying beyond January, but Arsenal will not sell him unless they can bring in a replacement, with a £35m bid for 20-year-old Malcom expected this week.