He has started to re-find his form back at BVB since a January loan move and was particularly influential in the Champions League, putting on a dribbling masterclass as Dortmund knocked out PSG to reach the final.
Arsenal are known to be in the market for a new winger this summer, with Mikel Arteta keen to sign someone capable of providing cover and competition for Bukayo Saka, and Petit feels the reborn Sancho ticks plenty of boxes.
‘I was saying how impressed I was with Jadon Sancho in the Champions League on commentary,’ Petit told Grosvenor Sport.
‘He looks like a new player, so fit, thin and explosive.
‘He’s like dynamite on the pitch, so explosive on the ball with [Karim] Adeyemi on the left flank, so hard to catch.
‘He’s back to his best and Man United look so far away from them, so if Arsenal want him, why not?
‘You can put the best player in the world at Man United at the moment and they’d look average in two months.’
On United’s plethora of underperforming players, he added: ‘This is easily the worst Man United side I’ve ever seen.
‘So many average players and Casemiro looks so poor. I don’t recognise the master midfielder he used to be.
‘It must be so hard to be a Man United fan when you see the history of the club. They must be thinking: “What is going on?”
‘You can see their body language with each other and just not good enough.’
Sancho’s future at Old Trafford is likely to be dependent on what happens with Ten Hag, with the Dutch coach under considerable pressure after a huge downturn in form in recent weeks.
United have won just one of their last eight Premier League matches, leaving them eighth, and were very nearly embarrassed by Coventry City at Wembley. Should they change managers, it might open up a way back into the fold for Sancho.