Heath Herring will end his eight-year layoff in less than two weeks.

The former UFC heavyweight will compete in the quarter-finals of the Rizin FF open-weight grand prix tournament on Dec. 29, an unnamed source told BloodyElbow.com on Sunday. Herring joins the likes of Mirko Cro Cop, Shane Carwin and Muhammed Lawal, who are all competing next week, as well.

It isn’t clear who Herring will be fighting in the second round of the tournament.

Herring hasn’t fought since a 2008 loss to former UFC champ Brock Lesnar. Herring, who also competed for PRIDE FC, compiled a 2-3 record inside the Octagon, with wins over Cheick Kongo and Brad Imes.

Herring told Sherdog.com last year that he never actually officially retired, but did indeed elect to wait for his UFC contract to expire in 2009. He said that he was considering a return to the cage, but nothing was in the works at the time.

Herring attended Rizin FF’s first two events at the end of 2015 and served as one half of the commentary team at the organization’s most recent event, Rizin FF 2, this past September.

The Rizin FF tournament kicked off at Rizin FF 2 in September. Six fighters advanced to the quarterfinals at that event, including Cro Cop, Jiri Prochazka, and Amir Aliakbari.

Following the quarter-finals, the semi-finals and finals of the tournament will take place two days later on New Year’s Eve.

Rizin FF’s upcoming pair of shows, Rizin FF 3 and Rizin FF 4, both take place at Saitama Super Arena in Saitama, Japan.