It has been rumored for months that Brock Lesnar will take on The Undertaker and his undefeated streak at WrestleMania XXX on Sunday, April 6 live from the Mercedes-Benz Superdome in New Orleans, but new reports indicate that there may be some doubt within the WWE that the match can happen due to Undertaker's declining health, and Sheamus may be a replacement.

It had been reported in recent weeks that the WWE had originally planned to have Lesnar take on The Big Show at the Royal Rumble on Jan. 26 and use his win over The Big Show to look strong heading into a feud with The Undertaker culminating at WrestleMania, however Wrestlingheadlines.com reports that the WWE may be changing their plans.

The report indicates that the original plan was that The Big Show was supposed to face Lesnar at the Royal Rumble and that the build was supposed to start during Big Show's feud with The Authority.

The original plan called for Show to go through Triple H and Randy Orton, but not win the title, in order to look strong heading into the Royal Rumble. He was then slated to lose to Brock Lesnar at the Royal Rumble in order to make Lesnar look even better for his battle with The Undertaker.

Now, the WWE is concerned about having a Lesnar and Undertaker match at WrestleMania XXX due to The Undertaker's declining health. Lesnar, who left the WWE in 2004 and began an MMA career, is very physical in the ring and WWE officials are worried that due to Taker's escalating age and declining health, that the match may be dangerous for the man from the darkside.

This led to speculation in November that Sheamus may be the one to take on The Undertaker at the event instead, and Sheamus himself even said he would love to face him at WrestleMania XXX. Sheamus has been recovering from shoulder surgery but should be back sometime within the next month.

"I'd definitely like to take on The Undertaker," Sheamus told NOLA.com in November. "That's definitely a dream of mine. I just feel like I can bring a new dynamic in there with him."

Another issue that came up with a Lesnar vs. Undertaker match, according to Wrestlingheadlines.com, is that a lot of Undertaker's opponents--if not all--over the past few years at WrestleMania have secretly worked out their match with him and practiced it leading up to the big event, and it's unknown if Lesnar would want to put in that sort of preparation.

It remains to be seen what happens at WrestleMania XXX, but if The Undertaker and Lesnar match is canceled, the dead man may take on Sheamus.