Benson Henderson (19-2 MMA, 7-0 UFC) and Anthony Pettis (16-2 MMA, 3-1 UFC) will meet again, but this time the UFC lightweight title will be on the line.

MMAjunkie.com (www.mmajunkie.com) today learned from sources close to the fight and subsequently confirmed with UFC President Dana White that T.J. Grant (21-5 MMA, 8-3 UFC) has been forced to withdraw from a planned UFC 164 contest with Henderson, and Pettis has agreed to step into the open slot.

UFC 164 takes place at MIlwaukee’s Bradley Center on Aug. 31, four weeks after Pettis’ expected UFC 163 featherweight title bout with Jose Aldo in Rio de Janeiro. Injury forced Pettis out of that fight, but Grant’s poor fortune now allows “Showtime” a chance to fight in his hometown in a bid for the UFC lightweight title.

While the nature of Grant’s injury wasn’t immediately known at the time of the initial report, the Canadian later took to Twitter to blame a concussion for his fate.

“Thanks everyone for your concerns,” Grant wrote. “I am healing from a concussion I suffered in BJJ of all things. I hope to be back training very soon.”

Henderson and Pettis, of course, have a history together, as “Showtime” scores a unanimous decision win over “Smooth” in the now-shuttered WEC’s final event to become the promotion’s final champion. Henderson hasn’t lost since, reeling off seven straight wins en route to claiming the UFC lightweight title in February 2012 and already racking up three successful defenses of the belt. Pettis, meanwhile, lost his UFC debut but has rebounded in style with three straight wins, including back-to-back “Knockout of the Night” wins over Donald Cerrone and Joe Lauzon.

UFC 164’s main card, including Henderson vs. Pettis, airs on pay-per-view following prelims on FOX Sports 1 and Facebook. The evening’s bout order has yet to be confirmed, but the lineup now currently includes:

Champ Benson Henderson vs. Anthony Pettis – for UFC lightweight title Josh Barnett vs. Frank Mir Clay Guida vs. Chad Mendes Erik Koch vs. Dustin Poirier Ben Rothwell vs. Brandon Vera Gleison Tibau vs. Jamie Varner Chico Camus vs. Kyung Ho Kang Nikita Krylov vs. Soa Palelei Tim Elliott vs. Louis Gaudinot Derek Brunson vs. Yoel Romero Magnus Cedenblad vs. Jared Hamman Pascal Krauss vs. Hyun Gyu Lim Ryan Couture vs. Quinn Mulhern

For more on UFC 164, stay tuned to the UFC Rumors section of the site.

(Pictured: Anthony Pettis)