By Edward Chaykovsky

Carl Froch's retirement was expected but nobody knew exactly when it would happen. Froch made it official very early Tuesday morning in the UK (late Monday night in America). 

Froch's career will be defined by many things. The former world champion known as "The Cobra" admits that his two-fight series with domestic rival George Groves will be the defining moment of his pro career.

In their first fight in 2013, Froch was dropped hard in the first round and was down on the cards when he secured a controversial ninth round stoppage win.

The controversial fueled a huge rematch in May of 2014, which drew a massive crowd of 80,000 fans to Wembley Stadium in London. The fans watched a close pitched battle where Froch landed a perfect shot in the eight round to knock Groves out.

The meetings with Groves would be the final ring moments of his career.

"Obviously it would have been nice to box the guy and beat him [in a third bout]. He hasn't been boxing since our fight. I knew his retirement was coming. How will he be remembered? He will be remembered for the controversy in our first fight, it was a wrong decision...obviously him beating me at Wembley....and him explaining it to Floyd Mayweather. Once you've explained it to Floyd Mayweather, I don't think there is much left to do in a boxing career," Groves told Sky Sports.

"We don't need to be friends, I have friends. There is a rivalry when you box, but now that rivalry isn't there. Rivalries are healthy in boxing. It promotes fights to become better fights."

"Carl Froch is a tough, strong man. Very tough. I don't know how he would have gone on with [the British greats]. I don't think he would have ever beat [Joe] Calzaghe. Calzaghe was a bit too quick for him. Him and [Nigel] Benn would have been a war, but Benn had a bit of more skill and class about him. That would have been a great fight to watch. It's one of those things that you never [how the fights would have turned out]. He's a tough man to beat, Carl."

Groves will aim to make his own mark next month, when he faces Badou Jack in Las Vegas for the WBC super middleweight championship.