Besic, 25, was loaned to Championship promotion contenders Middlesbrough last season for the second half of the campaign and was crucial in their play-off bid - but could do nothing in preventing Villa from their semi-final win.
Still out of favour at Everton despite a change of managers, Besic has been linked with a whole host of Championship clubs this summer as he remains firmly down the pecking order.
The returning James McCarthy pushes Bosnia international Besic even further down the list, behind the likes of Morgan Schneiderlin, Tom Davies, Idrissa Gueye and Beni Baningime.
Now, Boro are set to reunite themselves with the former Ferencvaros man, for a fee of £6million as Boro see of competition from the rest of the Championship to land Besic's signature.
It is believed that a permanent move between the two clubs is expected to go through today, despite only six hours remaining in the transfer window.