The two Americans will clash with Crawford's WBO welterweight title up for grabs in what is expected to be one of the biggest boxing events of the year.
Crawford, 34, and Porter, also 34, first met as teenage amateurs at the US Olympic try-outs, and were once close friends.
So much so they spent many hours playing basketball together in Porter's hometown of Ohio, approximately an 11-hour drive from where Crawford grew up on the streets of Omaha.
However, it seems to be that is no longer the case, as both have set aside their friendship for the sake of personal glory.
When asked if he has completely thrown it out the window, Crawford told Sky Sports: "Definitely. It was gone when we signed the contract.
"I don't have to disrespect him or talk bad about him. But we both know.
"There are no friends in the ring. The guy across from you is trying to knock your head off. I'm trying to knock his head off."
And while some have suggested Porter will be his toughest opponent yet, Crawford doesn't seem to see it that way.
The 34-year-old added: "We'll have to see if this is the toughest fight of my career.
"I've been faced with a lot of people who thought the past couple of fights would be the toughest. But we don't know until we step in the ring.
"I don't tend to listen but I do take heed because it means I won't overlook anything."
With that being said, Crawford is predicting good competition from Porter, but he also hinted he has a few tricks up his sleeve, just like he did in his victory over Kell Brook.
He said: "I believe, deep down in my heart, that there are a lot of things I haven't shown yet because I didn't have to show it at that point. There are skills I haven't had to display.
"Maybe Porter can bring those out. There is more to come. I am getting better.
"I expect Shawn to be Shawn - I can't stress enough how talented he is. He likes to box, he likes to bang, he likes to brawl. We will be ready for everything."News Now - Sport News