Ex-UFC heavyweight champ Andrei Arlovski (21-10 MMA, 10-4 UFC) is returning to the promotion six years after he left the industry-leading promotion.

UFC President Dana White today announced the return of “The Pitbull,” tweeting, “Welcome back, Andrei Arlovski!”

MMAjunkie subsequently confirmed with a source close to negotiations that Arlovski was released from his contract with World Series of Fighting and is targeted for a UFC 174 bout opposite Brendan Schaub (10-3 MMA, 6-3 UFC). The source asked not to be named because he was not authorized to publicly discuss the matter.

UFC 174 takes place June 14 at Vancouver, British Columbia’s Rogers Arena. The event’s main card airs live on pay-per-view following prelims on FOX Sports 1 and UFC Fight Pass.

Arlovski returns after running out his contract with the UFC and then signing with the now-defunct Affliction Entertainment. He earned a knockout over Ben Rothwell in the promotion’s debut and then did a one-off with the also-defunct EliteXC, knocking out Roy Nelson. He then went on to face Fedor Emelianenko in Affliction’s second event, and despite a spirited effort, was knocked out in the first round.

Upon Affliction’s shuttering in 2009, he went on to sign with the now-defunct Strikeforce and subsequently lost three straight high-profile bouts, including a first-round knockout to Sergei Kharitonov in the opening round of Strikeforce’s heavyweight grand prix.

Arlovski then rebuilt himself in smaller promotions, going 6-1 with one no-contest. He was among the first high-profile signees of WSOF and went 2-1 for the promotion, suffering a broken jaw and decision loss to Anthony Johnson at WSOF 2.

Arlovski’s most recent performance came this past November in his native Belarus, where he earned a second-round TKO of Andreas Kraniotakes.

Now 35 years old, Arlovski won the interim title at UFC 51 by submitting Tim Sylvia and then was promoted to undisputed champ following a first-round KO of Justin Eilers at UFC 53.

Schaub’s previous fight came this past September at UFC 165, where he choked Matt Mitrione unconscious to earn his second straight win. The veteran of “The Ultimate Fighter 10” carries a 6-3 octagon record.

For more on UFC 174, stay tuned to the UFC Rumors section of the site.

(Pictured: Andrei Arlovski)