The super-middleweight takes on Dirrell for the vacant IBF world title in Boston on May 23, live on Sky Sports, and he wants to add a world championship title to his Olympic gold medal from Beijing in 2008.
He would become the first British boxer to achieve such a feat.
Dirrell (25-1, 16 KOs), who won an Olympic bronze in Athens in 2004, has never been a world champion and lost a split decision to Carl Froch in Nottingham in 2009.
And DeGale is adamant that he will make history this weekend.
He said: ???It???s a chance that I can???t let slip; I???m too good. People aren???t going to give me the opportunities again because I???m too good. No one is going to fight me for a voluntary defence so I???ve got to take this chance.
???History is going to be made, I???m telling you. I???ve trained too hard, I???ve come too far in my career.
???You probably hear this a lot but I???m destined to be a world champion. Trust me, history is getting made on the 23rd, next Saturday.???
DeGale was speaking from Miami where he is finishing up his training camp before the bout.
???I???ve been over here for just over a week now,??? he said. ???I???ve just come over here to acclimatise and do my last bits of training, last bits of sparring, last bits of road work so I???m feeling good. I???m feeling real, real good.???