Boro confirmed on Wednesday evening that they were happy with Wigan's offer and Cattermole, who progressed through the Academy at the Riverside but has struggled for first-team action in the past 12 months, must now decide if he wants to leave his hometown club.
A Middlesbrough club spokesman said: "Boro have confirmed that they have agreed a fee with Wigan Athletic for the transfer of Lee Cattermole.
"The 20-year-old midfielder has been given permission to talk to Wigan, discuss personal terms and have a medical. No further news is expected until next week."
If Cattermole makes the move to Lancashire then it would free up the funds for boss Gareth Southgate to swoop for midfield target Harper in time for he new season.




