Gabriel Magalhaes' performance against Manchester United on Sunday has handed Ole Gunnar Solskjaer's side a reminder of what they missed out on in the summer.
Arsenal completed the signing of Gabriel from Lille for £27m, but the defender's agents held talks with United chiefs, according to reports.
The Brazilian centre-back was one of the standout performers for the Gunners as they narrowly beat Man United 1-0 at Old Trafford at the weekend.
The 22-year-old looked assured, aggressive and composed for Mikel Arteta 's side, who kept their first clean sheet in the Premier League since the opening day win over Fulham.
Gary Neville, who was on commentary duty for Sky Sports, heaped the praise on the "best player on the pitch" Gabriel during the match.
The former Manchester United defender said: "Arsenal's defensive performance has been brilliant, from front to back, but the back-three have been good.
"Gabriel has been fantastic, so far I'd say he's been the best player on the pitch, for me."
Going back to a tweet from RMC Sport journalist Mohamed Bouhafsi at the start of August and he claimed United's "leaders", which could mean Ed Woodward, were in discussions with Lille over the talented central defender.
As well as that, Everton and Napoli were also looking at bringing in Gabriel, but Arsenal ended up winning the four-club battle for his signature.
The former Brazil Under-20 international has played six times so far for the Gunners in the Premier League - missing just the one match - the 3-1 loss against Liverpool back in September.
Gabriel scored his first Arsenal goal on his competitive debut for the side, with a towering header against Fulham on the opening day of the 2020/21 campaign.
