Sanchez is a doubt for upcoming games against Sunderland and Olympiacos.
The manager says the striker has been "nowhere near as good as he was last year" due to speculations.
Dimitri Payet and Enner Valencia are also out for the trip to Old Trafford on Saturday .
Gary Neville will be in attendance to watch his new team take on the Spanish and European champions.
Midfielder won't return until the spring at the earliest as the Gunners' injury list grows.
Rafael Benitez's side will look to put a week of controversy behind them by beating Getafe.
Sadio Mane is being scouted by Bayern Munich for a move in January.
Lee Sharpe has pinpointed Wayne Rooney's failure to stick to the basics as the main reason for his poor form.
Marouane Fellaini and Ander Herrera have struggled for regular game time under Louis van Gaal this campaign.
Thibaut Courtois will displace Asmir Begovic in the starting line-up against Bournemouth.
Saido Berahino has been a subject of interest to Tottenham since last summer's transfer window.
Renault's Lotus takeover is not completed and will be done 'in the shortest time frame possible.'
Louis van Gaal is likely to step up their search for a left-back in January after Rojo injury blow.
The 92-count indictments allege 'racketeering, wire fraud and money laundering conspiracies'.
Experienced centre-back was only recalled from his loan spell at Wolves earlier this week.
Uruguay striker also claimed he wouldn't leave the Nou Camp even for three times the wages.
Laurent Koscielny and Theo Walcott may be available to make the squad.
World champion will be stripped if he rejects mandatory defence against Vyacheslav Glazkov in favour of Klitschko clash.
Former Manchester United defender was appointed as Nuno's successor on Wednesday.
Germany international is no closer to agreeing a new contract which expires in 2017.
Mauricio Pochettino has confirmed that Nabil Bentaleb and Nacer Chadli are close to training comebacks.
Under-21 coach Warren Joyce says youth players are excelling amid regular contact with seniors.
Lewis Hamilton has won the last two championships, with teammate Nico Rosberg finishing second both times..
AP found that viral levels in Rio waters were 30,000 times higher than levels thought to be alarming.
The Gunners reportedly made an approach to the Barca starlet in the summer transfer window.
Sam Allardyce expects Jack Rodwell to return to training on Friday but Sebastian Larsson is still out.
Mauricio Pochettino admits the January window is 'hard' and that Spurs must be careful.
Xavi also hit out at Louis van Gaal's treatment of his former teammate ahead of the January window.
The 33-year-old is eyeing a return to the game after seeking psychiatric help following troubling spell.
Arsenal are currently without five first-team midfielders due to injury.