The Cameroonian international moved to Boro under Bryan Robson's regime in a £3 million deal from Lens in 2000. But after a relatively prosperous start he fell out-of-favour at the club.
The appointment of Steve McClaren led to a new chance for the winger and he featured in pre-season and the opening few games of this season.
However, the 24-year-old has again failed to hold his place in the first team squad and has not featured since early September.
A move back to France would certainly appeal to Job, who played for Lyon before joining Lens, and Metz are set to take him back on loan for the rest of the season with a view to a permanent switch.
Boro are desperate to lighten their wage bill, which would enable McClaren to add to his playing staff.
