Diamond is on loan at League Two side Harrogate Town and has impressed so far, hitting the back three times in twelve league outings, as well as providing two assists.
The 21-year-old scored and provided an assist as he side beat Rochdale earlier this month and Harrogate are putting together a promotion challenge.
Harrogate could lose Diamond in the new year though as the season-long loan agreed contains a clause which would let Sunderland recall him in January.
It is claimed that Sunderland boss Lee Johnson is considering bringing Diamond back to the Stadium of Light in a bid to help his options at wing-back.
Diamond has experience playing as a wing-back under Johnson and could be given another opportunity in the role in the new year.
However, Johnson could opt to dip into the free agent market to bolster his options.
Johnson though is well aware of Diamond’s talents and the winger trained at Sunderland for two days over the recent international break, giving the manager another up-close look.
Losing Diamond would be a blow for Harrogate, but they could look to replace him in the January window.