That’s according to Football League World who claim the Blues are one of a host of clubs keeping tabs on the 25-year-old ahead of a possible move in the January transfer window.
Among those supposedly competing with Pompey for the Grecians youth product ace are League One rivals Ipswich – along with Championship sides Barnsley and Millwall.
It has been reported that 20 clubs have already send scouts to watch Exeter’s current top goalscorer as they weigh up possible moves.
Jay has scored five goals in all competitions to date this season as he bids to maintain the form displayed during his breakthrough campaign as a key Grecians performer.
Last term he scored 20 goals in all competitions as Exeter finished ninth in the League Two table.
Pompey boss Danny Cowley will no doubt be looking to add to his attacking options in January after a slow start to the season.
At present Marcus Harness is operating as the Blues’ main attacking midfielder and scored in Saturday’s 2-2 draw at Charlton.