BJ Penn vs. Dennis Siver set for UFC 199

BJ Penn is back.

According to Yahoo Sports' Kevin Iole, the former UFC welterweight and lightweight champion Penn will face Dennis Siver June 4 at UFC 199 in Los Angeles.

MMA Fighting's Ariel Helwani confirmed with sources that the fight will be at 145 pounds.

This news comes following a recent internal investigation by the UFC into sexual assault allegations made against Penn. According to UFC Chief Operating Officer Lawrence Epstein, these allegations could not be substantiated, and the organization will allow Penn to compete unless contrary evidence arises.

"We have taken a look at the available facts, which aren't too substantial, and there are two stories of what happened," Epstein told Iole. "To date, there has [been] no action at all taken by any law enforcement agency. We decided to allow B.J. to fight. However, we are going to continue to monitor to the situation. If new information, more information, becomes available to us, obviously, we reserve the right to re-evaluate."

Penn (16-10-2) returns to the cage after a near-two-year layoff. The Hawaiian announced his apparent retirement from the sport following a lopsided TKO defeat to Frankie Edgar at The Ultimate Fighter 19 Finale in July 2014, only to resume training at Team Jackson-Winkeljohn MMA in early 2016.

Now, Penn finally has his official matchup with Siver (22-11, one no-contest).

Since an October 2014 decision victory over Charles Rosa, Siver has suffered back-to-back defeats, falling to Conor McGregor via knockout and to Tatsuya Kawajiri more recently via unanimous decision.

Similarly, Penn is just 1-3-1 in his last five, with the lone victory coming against Matt Hughes in November 2010 at UFC 123.

UFC 199 is headlined by a UFC middleweight title rematch between newly crowned champ Luke Rockhold and Chris Weidman. A co-main event bantamweight title fight between champ Dominick Cruz and challenger Urijah Faber bolsters the top of the card.