Sanchez was a doubt for the game against Manchester United on Saturday due to a hamstring injury.
The 27-year-old picked up the knock while on international duty with Chile but was named in Arsene Wenger's starting XI at the weekend.
And Wenger has since defended his decision to play Sanchez in the 1-1 draw at Old Trafford despite him not being 100 per cent.
"It's very unusual [for me to use an injured player]," Wenger said after the game.
"But I did it because Sanchez is a guy who can take people on and I knew that would be a quality.
"He is good in counterattacks in short spells as well. He is always a player who is not scared of anybody.
Olivier Giroud celebrates Arsenal draw at star-studded gala
Sun, November 20, 2016Click through the gallery for the best snaps of Olivier Giroud celebrating his Arsenal equaliser against Man United
Giroud arrived at the Global Gift Gala in London on Saturday night alongside his wife Jennifer
"I think he played very well in the first half. In the second half, we didn't give him enough service.
"But overall, for a guy who has played a decisive game on Tuesday for Chile, or basically Wednesday morning, travelled after and had jet lag, it's remarkable that he was able to play as he did."
Sanchez has been in stunning form this season for Arsenal since being moved into a more central attacking role.
The South American has scored eight goals and provided seven assists in 16 appearances for the Gunners.
However, he was largely ineffectual against United at the weekend, and Wenger was forced to call upon Olivier Giroud from the bench.
The Frenchman came on a snatched a late equaliser on the 89th minute - his third Premier League goal from the sidelines this term.