Jorge Santiago is back in Strikeforce.

The Brazilian fighter has signed a new multi-fight deal with the organization, and he will meet Quinn Mulhern on Sept. 29 in Sacramento, Calif., according to company officials. The fight will mark Santiago's welterweight debut.

Santiago (25-10) won the Strikeforce middleweight grand prix in 2007 after defeating Sean Salmon and Trevor Prangley on the same night. He was released from the UFC, whose parent company Zuffa also owns Strikeforce, for a second time in Oct. 2011 and has since gone 2-0 outside of the organization.

Mulhern (18-2), who first announced the news about the matchup via Twitter, is 3-0 in his last three fights. The former King of the Cage welterweight champion holds notable wins over veteran Rich Clementi and Yuri Villefort.

Strikeforce's September card will be headlined by Gilbert Melendez vs. Pat Healy. It's unclear at this time whether Santiago vs. Mulhern will air on the main card.