Hector Bellerin is currently out of the squad with an ankle injury.
Manchester United are currently in sixth position in the league.
Sanchez has scored 14 goals this season.
Wenger admitted it is 'unusual' for him to play an injured player.
Gunners fought back to draw 1-1 with Manchester United at Old Trafford on 19 November.
Santi Cazorla missed the last two games for Arsenal.
Arsenal had just one shot on target during the course of the 90 minutes against United.
Sanchez had one full training session after returning from international duty with Chile.
Wales midfielder admits Arsene Wenger's reputation of nurturing young players swayed his decision.
Bellerin suffered the ankle injury during Arsenal's 1-1 draw against Tottenham.
Alexis has scored eight goals thus far this term.
French boss points out Marcus Rashford was the one who 'killed' the Gunners last season.
United are six points behind the Gunners in the Premier League table.
Gunners visit Old Trafford on Saturday before Champions League clash with Paris Saint-Germain.
Alexis Sanchez picked up a minor hamstring injury while on international duty with Chile.
Ozil currently earns £140,000-a-week at Arsenal.
Giroud has scored two goals in the league thus far.
Arsenal face Manchester United at Old Trafford after the international break.
Having missed out against Colombia, Arsenal star is likely to feature for struggling La Roja against Uruguay.
German champions are worried Arturo Vidal will play despite being stretchered off.
Shkodran Mustafi has not lost a single game since joining Arsenal.
Perez has scored two goals thus far in the EFL Cup.