The 17-time capped Nigerian international, still only 20, enjoyed a spell at the Riverside Stadium last season, shoring up Boro's backline upon the arrival of Aitor Karanka.
He spent his summer in Brazil, at the heart of the Nigerian defence, as he led his teammates to a Round of 16 finish, exiting to France in the World Cup.
Whilst many were calling for his inclusion into the Chelsea first-team this season, the arrival of Kurt Zouma earlier in the year has pushed the youngster further down the pecking order and Karanka used his friendship with Blues head coach Jose Mourinho to secure the Nigerian on loan until the end of the 2013/14 season.
Already a fan favourite on Teeside following his displays last season, the Boro faithful were surprised to see Omeruo on the bench on opening day - with England Under-21 international Ben Gibson starting in his place.
However, Gibson suffered an injury in the opening minutes and Omeruo entered the game as his replacement, with just four minutes on the clock - and it was if he had never left.
Whilst his defensive partner Daniel Ayala took the plaudits for his goalscoring exploits, Omeruo solidly led from the back, winning more tackles and interceptions than his teammate, and managing to not even commit one foul. He willingly attacked every ball, both on the ground and in the air, and looks far too good for the Championship - not surprising, considering he was playing against Lionel Messi, Karim Benzema and Angel Di Maria in the summer.
If the youngster is to have an impact at Chelsea, this could be his last year to impress. Despite his young age, the wealth of defensive talent at Stamford Bridge is unlikely to disappear, and he may be required to move on to pastures new. However, he has proven that he is more than good enough to play on the world stage, and Blues fans will be hoping that a season at the heart of the Middlesbrough defence will be the catalyst for the start of Omeruo's top flight career.