The 35-year-old Arlovski last fought in the UFC in March 2008 when he beat Jake O'Brien by TKO at UFC 82.
UFC president Dana White heralded Arlovski's return in a tweet Thursday night that read: "Welcome back Andrei Arlovski!"
The Canadian Press has learned the former champion will start the next phase of his UFC career on June 14 in Vancouver against Schaub.
The main event of the Rogers Arena card has Demetrious (Mighty Mouse) Johnson defending his flyweight title against No. 4 contender Ali Bagautinov of Russia.
Arlovski (20-10) debuted at UFC 28 in November 2000, compiling a record of 10-4 that includes victories over Fabricio Werdum and Tim Sylvia. He beat Roy (Big Country) Nelson and (Big) Ben Rothwell outside the UFC.
Arlovski had a trilogy of fights with Sylvia, winning one and losing two. The first at UFC 51 in February 2005, earned him the heavyweight title.
Arlovski defended the crown twice before losing it to Sylvia at UFC 59 in April 2006. Sylvia beat him again at UFC 61.
Arlovski is 6-1 with one no contest in his last eight fights. He is 8-5 with one no contest since leaving the UFC.
Schaub (11-3) has won his last two UFC fights over Matt Mitrione and Lavar Johnson. The 31-year-old former University of Colorado fullback is 6-2 in the UFC since losing to Nelson in the finale of "The Ultimate Fighter" Season 10.