The Eredivisie club has bolstered its ranks following the summer departures of Dries Mertens, Jeremain Lens and Erik Pieters.
PSV Eindhoven has completed the signings of Jeffrey Bruma, Stijn Schaars and Santiago Arias.
Bruma, 21, joins on a four-year deal from Chelsea, while Schaars, 29, and Arias, 21, have signed three- and four-year deals, respectively, after arriving from Sporting Lisbon.
The trio continues the Eindhoven club's rebuilding process following the signing of AZ midfielder Adam Maher on the back of losing Dries Mertens, Jeremain Lens and Erik Pieters earlier this summer.
Bruma, who is thought to have cost in the region of 3 million euros, has impressed in his last two seasons spent on loan at Bundesliga outfit Hamburg, and PSV will be hoping he can further his growing reputation in Eindhoven.
"[Bruma is] a defender that we would have wanted sooner," PSV technical director Marcel Brands told the club's official website. "Unfortunately, it took a little longer than we had hoped for, but we are pleased that he is here."
Schaars, who played for Vitesse and AZ earlier in his career, returns to the Netherlands after a two-year spell in Portugal as part of a double 1.6 million euro deal with Colombia right back Arias.
"It was a difficult operation with Sporting, but we can add a chunk of experience in the team with him," Brands added about the midfielder. "From the first day we approached Stijn, he could not wait to start."