#8 Goldberg

It is a little-known fact that Goldberg was almost in the main event of WrestleMania, and yes, it would have been with Brock Lesnar, but no, not WrestleMania 33 in 2017.
Goldberg vs. Brock Lesnar had been planned for WrestleMania XX since pretty early on in 2003, not long after Goldberg arrived in WWE in fact.
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Up until towards the end of the year, the plan was for Goldberg to win the 2004 WWE Royal Rumble, and then jump ship to Smackdown, where he would have challenged reigning WWE Champion Brock Lesnar, for the Championship in the main event of WrestleMania XX.
However, Goldberg had heavily implied to WWE officials as early as December 2003, that he would likely not be re-signing with WWE when his contract was to expire the night of WrestleMania.
Although the Goldberg vs. Lesnar WrestleMania match still happened, plans changed for back up Chris Benoit to win the Rumble and headline the event. Goldberg and Lesnar would take place much earlier on the card and as we all know, failed to deliver on any and every level.