In October 1998 Nightingale was named as an unused substitute for the home tie against Bradford City with no reserve team experience behind him.
The next day after the Reading game Nightingale signed a 4-year professional contract under boss Alan Ball, before his debut against West Brom on 21 November.
He also opened the scoring for Pompey in an FA Cup tie at home to Leeds United in January 1999, although the Yorkshire club hit back to win 5–1.
He then teamed up with his old Portsmouth teammate Steve Claridge who was appointed player/manager at Weymouth in the Dr Martins League.
Following limited first team opportunities at Havant he rejoined Bognor Regis Town for the remainder of the 2010 season, then signing for the Rocks on a permanent basis for 2010–11, scoring 26 goals in 38 starts.