Ajax coach Frank de Boer has highlighted PSV's new signing Dries Mertens as a potential danger man ahead of Sunday's showdown.
The Belgian winger, who arrived in Eindhoven from FC Utrecht this summer, is the Eredivisie's current top scorer, having already netted seven goals for PSV this season.
Mertens also helped get their Europa League campaign off to a winning start, scoring the only goal to seal a 1-0 win over Legia Warsaw on Thursday night.
Reigning champions Ajax travel to the Philips Stadion this weekend and De Boer is wary of their rivals' recent purchases, identifying Mertens as a particular threat.
"They have spent wonderfully," De Boer told Ajax's official website.
"They have attracted Dries Mertens, amongst others. He was decisive against Legia Warsaw yesterday.
"The midfield of PSV is very good. They have many good players and as a team they are still growing."
"They have a good team and are candidates for the title."