That is according to French football expert and ESPN FC pundit Julien Laurens.
Manchester United welcome PSG for the Champions League last 16 first leg on Tuesday night.
The Ligue 1 giants have seen their preparations disrupted due to injuries to Neymar and Edinson Cavani.
Kylian Mbappe is likely to play a central role in the absence of Cavani.
Laurens says PSG will look for space in behind the United defence for Mbappe to run into.
And he reckons they will target the two full-backs, who are set to be Ashley Young and Luke Shaw.
“PSG will be hoping they can exploit the space in behind for Kylian Mbappe to run into,” Laurens said.
“Behind [Victor] Lindelof and [Eric] Bailly but also behind the two full-backs that PSG see as the main weakness for this United team, Shaw and Young.
United interim boss Ole Gunnar Solskjaer says injuries to PSG stars Neymar and Cavani have made preparations more difficult for his side.
“Any team that is missing players like Neymar, Cavani, [Thomas] Meunier will miss them,” he said.
“But it gives other players a chance. It makes it more unpredictable for us, who they will play.
“When you see that front three, you know how they will play so we are guessing a bit.
“It is difficult to compare games because when they play in the league, they know they are going to win it anyway so they approach it differently to the Champions League.
“But it is always nice to see players live, you see different spaces, principles – you saw how lightning quick Kylian Mbappe is.
“You try to do due diligence.”