WrestleMania 31, the biggest annual pay-per-view event of the WWE, is scheduled to take place on March 29, 2015 at the Levi's Stadium in Santa Clara, California. But while, the huge event is looked forward to for its compelling storylines, the burning question making the rounds heading into WrestleMania 31 is: Will WWE World Heavyweight Champion Brock Lesnar continue to work with the company following the event?

According to Inquisitr, Lesnar is booked for "Monday Night Raw" on March 30, the night following WrestleMania, which is reportedly the last day he is scheduled to work under his current WWE contract.

There have been a constant stream of rumors regarding Lesnar's possible return to MMA, which heightened in February of last year when UFC president Dana White said the former UFC Heavyweight champion hinted at his interest in returning to the octagon.

"If he wants to fight, he'll call me," White recently told John Pollock of the Fight Network, confirming that he spoke with Lesnar recently, which included a conversation just last month.

There have also been rumors of Lesnar returning to MMA, although, this time with UFC rival organization, Bellator. Both the UFC and Bellator are not officially allowed to negotiate with Lesnar before his WWE deal is up.

Sports World News reports that Lesnar could also move to MMA while remaining with the WWE on a part-time deal.

While emphasizing the uncertainty of the WWE World Heavyweight Champion's future, the sports news website opines that there is expected to be a bidding war for Lesnar's services following WrestleMania.

Lesnar held a 5-3 record while fighting under the UFC, which was derailed by diverticulitis"”a common digestive disease that involves the formation of pouches within the bowel wall.

The 37-year-old last fought for the UFC in December 2011, when he was stopped by Alistair Overeem in UFC 141.