According to reports in the Adelaide Advertiser, Gulum's wife, Emel, recently moved to Melbourne and gave birth to the couple's first child. 
Gulum has been regularly commuting between Adelaide and Melbourne and told United that he could potentially retire at the end of this season to move to Melbourne pemanently.
However, with Melbourne City looking to land the former-Turkish international for next season to strengthen their defensive options after the departure of Ruon Tongyik, Jakobsen may move the other way.
Gulum is currently on loan at Adelaide from Chinese outfit Hebei China Fortune, with the deal expiring at the end of this year, while Jakobsen could link up with former Danish international teammate Johan Absalonsen at Adelaide. 
The future of Reds youngsters Jordan O'Doherty and Jordan Elsey also seem uncertain, with Elsey in particular impressing greatly this season in Adelaide's backline.
Elsey - who was offered a new deal by Adelaide - has been linked with an Eredivisie club.