The Stourbridge boxer lost a controversial decision, and his IBF International super-welterweight title, to Ted Cheeseman in August after a thrilling fight.
It was his seventh loss in a 35-bout career that has seen the 27-year-old collect a number of British, Commonwealth, European and International titles.
But the world title still eludes him and Eggington hopes his upcoming battle with veteran Theophane can help propel him back into that conversation.
He said: “I’m still just 27 and I’ve accomplished so much in under 10 years as a pro, but the world title is the one thing that’s missing and I desperately want that more than anything else.
“Winning this fight is absolutely crucial to me and my future so there’s no ifs or buts, I have to win, full stop.
“I’m coming off the Cheeseman fight that I don’t believe I lost.
“I 100 per cent won that fight and the scoring was dreadful with everything hedging towards him.
“I’m now focused on Theophane who’s a good name.
“He knows the game inside out and he’s experienced and well travelled, we’re both solid pros and know what’s on the line.
“He’ll want to win bad and so do I, I’m not planning on it going the 12 rounds, I’ll be getting him out of there inside that.”
London-born Theophane is extremely experienced, having racked up 50 professional wins in his 17-year career – with only eight losses and one draw on his record.
The 40-year-old, who is the former British super-lightweight champion, has fought in dozens of countries and was previously promoted by Floyd Mayweather’s TMT outfit.
He has fought once for a world title, against American Adrien Broner for the WBA world super-lightweight title in April 2016, but Theophane fell short as he was stopped in the ninth round.
Now, he is coming off a win over former IBF world super-welterweight champion Kassim Ouma in October 2019.
Eggington and Theophane are headlining the new Hennessy Sports card, held in London, on December 11.
The 12-round contest will be shown on free-to-air Channel 5 and will be behind-closed-doors.