The Nigerian international has reportedly passed a medical at the Riverside club.
John Obi Mikel is set to make a shock return to English football, according to the Guardian, who are reporting that the midfielder has agreed terms with Middlesbrough.
The 31-year-old is a free agent after leaving Chinese outfit Tianjin Teda and has agreed terms with the Championship club, who currently lie fifth in the table.
Mikel played at Chelsea for eleven seasons, but could never quite reach the potential expected of him and moved to China two years ago.
The midfielder’s girlfriend and their daughters currently reside in London, the key contributing factor in his desire to return to England.
Mikel’s signing will bolster a Boro squad aiming for promotion to the Premier League, sitting six points behind second-placed Norwich City.