Nightingale resigned to Pompey exit
The 22-year-old was a teenage sensation four seasons ago, when he scored two goals as a 17-year-old substitute on his Pompey debut in a 2-1 win over West Bromwich Albion in Division One.
His early rise to fame earned him a four-year deal at the time with the South Coast club.
However, a knee injury kept him out for a year and Nightingale has found it difficult to break back into manager Harry Redknapp's first team this season.
Without a first team appearance for two years, the striker is already looking for a new club for next term, believing he will not get a fresh deal in the summer.
"My contract's up in the summer. Nothing's been said, but I presume I'm not going to be offered another one." Nightingale told The News.