Arsenal headed into the game at the Emirates experiencing a slight dip in form.
The Gunners drew with Southampton last weekend and lost to PSV on Thursday in the Europa League.
As for Forest, they are bottom of the Premier League, but did see off Liverpool last time out.
At the time of writing on Sunday, Arsenal have a 1-0 lead thanks to a goal from Gabriel Martinelli.
Martinelli switched play to Bukayo Saka before making a run into the box and heading in from a Saka cross.
After the goal, all the Arsenal players got together and pulled out a shirt with Pablo Mari’s name and number on the back.
This of course comes after the Spaniard was hospitalized earlier this week.
Mari, who is on loan at Italian club Monza, was one of six people attacked at a supermarket near Milan on Thursday.
The Spaniard suffered a deep cut to his back during the incident and local media report that he will undergo surgery on Friday.
The centre-back has since spoken out about the attack:
“Today I was lucky, because I saw a person die in front of me,” Mari is quoted as saying by Gazzetta dello Sport.
Monza president Adriano Galliani visited Mari on Thursday along with the Serie A side’s head coach Raffaele Palladino:
“He was probably saved from his height,” Galliani told local media outside the Niguarda hospital.
“Pablo is an amazing guy. He had the strength to joke, telling me that he will be on the field on Monday. I brought him greetings from President Berlusconi and everyone. His team-mates wanted to come here but obviously it was not possible.”
Speaking to Italian station TG2 RAI, Galliani added: “Pablo Mari has quite a deep cut to his back, but fortunately it did not reach any vital organs like the lungs or anything else.
“His life is not in danger, he should recover quickly. He has some lesions, but not very serious. He is conscious and getting stitches.”