The Serb is currently struggling to regain his place in Newcastle's first-team after receiving a three-match ban for elbowing West Ham's Manuel Lanzini in a 3-0 win at St James' Park back in August.
Summer signing Joselu is currently Rafa Benitez's first choice forward, while the Magpies' top scorer last season Dwight Gayle is playing the role of back-up after almost leaving the club on deadline day.
Mitrovic was left out of Newcastle's squad for the 1-1 draw with Liverpool before the international break.
And according to the Daily Mirror, Chris Hughton sent scouts to watch the controversial forward during Serbia's 3-2 defeat to Austria on Friday.
Brighton have enjoyed a mixed start to their life in the top flight but are lacking firepower up top.
Things were made worse for the Seagulls when main striker Tomer Hemed picked up a retrospective three-game ban for an alleged stamp on Newcastle's DeAndre Yedlin last month.
As for Mitrovic, his success on Tyneside is widely disputed among fans.
The former Anderlecht man has 17 goals in 36 appearances for the club.
But his lack of discipline and low work-rate has seen some of the St. James' Park faithful lose patience in him.
On Sunday, Newcastle take on Southampton at St Mary's while Brighton host Everton at the AMEX Stadium.
