It is understood the Teessiders have agreed a deal with the Gunners which could take the 24-year-old Frenchman to the Riverside Stadium.
However, the player is currently on holiday and has not yet discussed the proposed move.
Southgate tried to sign Aliadiere last season to bolster his striking resources, but having failed in his efforts to lure him away from the Emirates Stadium, turned instead to South Korean ace Dong-Gook Lee.
The Rambouillet-born frontman played a major role in Arsenal's Carling Cup campaign, but his first-team appearances were once again limited.
But with Mark Viduka's future uncertain - he is being heavily tipped to join derby rivals Newcastle with his contract due to expire within weeks - and Portsmouth boss Harry Redknapp being linked with a move to take Ayegbeni Yakubu back to Fratton Park, Southgate's need is pressing.
The Boro manager is currently on a two-week residential course at Lilleshall as he studies for his UEFA A Licence, while chairman Steve Gibson is on holiday and chief executive Keith Lamb was attending Friday's meeting of Premier League chairmen.
There was no comment on the matter from the club, but Southgate is known to have included the likes of Aliadiere and West Brom's Diomansy Kamara among his list of potential targets.