Aubameyang has been linked with a shock move to United this transfer window.
It comes amid interest in Romelu Lukaku from Inter Milan, who are desperate to snap up the Belgian on Antonio Conte’s wishes.
The former Everton forward is also keen on leaving after being told by Ole Gunnar Solskjaer that he is no longer first-choice.
But it means that the Red Devils will be looking for a replacement, and the pace of Aubameyang is something that attracts the Norwegian coach very much.
A move to Old Trafford would come as a shock to Arsenal fans, who would be reluctant to see their top goalscorer leave for one of their rivals.
The Gabon international was one of three players to share the Premier League Golden Boot last season, along with Sergio Aguero and Sadio Mane.
But Gunners fans have been told by former club coach and keeper Lehmann that it would be no big deal.
He said: “If you finish fifth [in the league] you can sell players.
“If he was to go to United, a new player would come in who could do better. Arsenal’s goal shouldn’t be to finish fifth or sixth.”
Arsenal did not have a great season last year as they looked to life after Arsene Wenger.
Unai Emery was tasked with filling the legendary Frenchman’s boots but the north London outfit failed to reach the top four and were also beat by Chelsea in the Europa League final.
And Lehmann has demanded that the current top at the Emirates step up and win some silverware.
He added: “All of the guys playing for Arsenal are good but they need to win something.
“They were in the Europa League final last season and lost. Obviously it would have been good if they had won it.
“Their finish in the league season was disappointing as well.
“Even though they had the chance to secure fourth place, or even third place, they didn’t.
“The club is in a situation right now where no one knows the direction that it is supposed to be going in.”