Pardew believes that the position of veteran centre-back Gary Cahill in the back-three appears to be the only issue with the current league leaders.
"The only slight weakness they have is this channel down [Gary] Cahill's side," said Pardew on Sky Sports.
"Because he [Azpilicueta] is a natural full-back, he can deal with what's coming down the side of the box. Cahill, not so much.
"And obviously, this [Marcos Alonso] is an inexperienced player who's had an unbelievable season.
"I don't think anybody would have assumed he'd do that role as well as he has.
"We looked to get in these pockets down the side of [Nemanja] Matic who hasn't got quite the legs of [N'Golo] Kante and then try and get to Cahill.
"But it's very difficult."