Former Strikeforce champion and UFC title challenger Jake Shields is not too fond of his WSOF 22 opponent Rousimar Palhares. The two grappling specialists are set to collide for the World Series of Fighting welterweight strap.

Both men formerly competed on the UFC's main stage and had mixed success in the organization. Shields joined the UFC with a mountain of hype behind him after he conquered the Strikeforce middleweight division and was expected to reign supreme over the bulk of UFC's esteemed contenders. Shields' venture into Zuffa territory proved to be anti-climatic, as the Gracie Jiu-Jitsu standout struggled to find his footing in MMA's premier promotion and exhausted fans with a series of lacklustre, dull Octagon outings. Since failing to capture promotional gold at UFC 129 against Georges St-Pierre, the Californian struggled to reclimb the welterweight ladder - collecting a mixed-bag of losses, uninspiring split-decision wins and a NC (no contest) for good measure.

The 170 lb. contender was released from the UFC after his loss to Hector Lombard in 2014. Since March of last year, Shields collaborated with WSOF and sprang back into the winners column. He netted two first-round commanding submission wins over Ryan Ford and Brian Foster.

Shields is expected to face Palhares this summer, here's what he had to say about his upcoming opponent to BJPenn.com:

"He's a dirty leg lock fighter - so I've been training for that. This fight's exciting to me, because it's a guy I don't like. It's nice to have someone you don't actually like - it makes it easier to train and I wanna go out there and hurt him. I think the fact that he goes out there and hurts people, not only in fights where it's serious, but in submission matches as well. Guys will tap and he'll still break their leg - in Abu Dhabi he popped a guys leg, he's just a dirty guy. He tries to be overly nice, but I think he's a sociopath. He does it over and over, it's something he enjoys doing," Shields said.

Rousimar Palhares earned his reputation during his stint in the UFC as one of the most vicious leg-lock specialists in the game. The hulking 170 lb. contender proved to be an intimidating opponent for any foe not thoroughly trained in the arts of submission defense; locking up hellacious heel hooks on his adversaries any time the fight hit the mat. The Brazilian is also notorious for holding onto submissions after his opponents had tapped and sometimes even seconds after the referee's intervention. This repeated unsportsmanlike conduct prompted the UFC to release him from the promotion in 2013.

The controversial grappling ace seized the WSOF welterweight title in 2014 against Steve Carl with his signature heel hook and reclaimed the title in December; forcing former UFC star Jon Fitch to succumb to a devastating knee-bar.

With both Shields and Palhares excelling on the ground, expect a showcase of high-level jiu-jitsu and grappling in the World Series of Fighting Octagon for their welterweight tilt on August 1st at WSOF 22.