Conor McGregor is the more prepared fighter for UFC 189 in Las Vegas, but all that was done supposedly in preparation for a bout against UFC featherweight champion Jose Aldo.

But with Aldo out because of an injured rib and McGregor facing a dangerous substitute in Chad Mendes, will the UFC be better off cancelling the fight?

Apparently, some believe the match should have been cancelled because a Mendes victory may waylay all plans of an Aldo vs. McGregor bout in the future.

This doesn't mean McGregor, the third-ranked UFC featherweight, will surely lose. In fact, it seems that the Irish martial artist is entering the match with a big advantage. But a surprise could occur, and Mendes is more than capable of making that happen.

If Mendes does pull out a win over McGregor, the UFC may have just killed one of the biggest featherweight matches in MMA history -- Aldo vs McGregor.

This was the match that was slated to happen. However, Aldo was forced to withdraw because of an injured rib, and Mendes was chosen to take his place. Though unprepared for the fight, Mendes agreed since the opportunity was simply too big to pass up.

Cocky as always, McGregor believes he can give Mendes a beating, though the actual scenario may be totally different. In a scenario favoring Mendes, the second-ranking UFC featherweight could ground the offensive-minded McGregor and once he does, that could spell trouble for the Irishman.

A Mendes win will ultimately mean he will be immediately scheduled to face Aldo instead of McGregor, a scenario that kills the botched fight.

The original billing would have been advantageous for McGregor since he would have to compete against an elite fighter. Now, he seems to be facing a must-win situation and the intense pressure that goes with it.

Mendes did fight Aldo before and lost. So if McGregor loses, then it technically makes him incapable of facing Aldo once the featherweight champion becomes 100% healthy.

That is of course getting ahead, but one has to admit that McGregor cannot take Mendes for granted, considering that he is the best wrestler in the 145-lb category.