One out at Wigan Athletic - and another to follow
and live on Freeview channel 276
However, he was unable to make his mark at the DW Stadium, and made only five appearances, including just one start - on the last day of the campaign against Rotherham.
The 24-year-old’s total time on the field totalled only 101 minutes.
“He’s a player with real experience of this level after enjoying a successful spell with Lincoln," said Pompey boss John Mousinho.
“He made a massive contribution in terms of goals and assists, which followed on from being one of the outstanding players for West Ham’s Under-21 side.
"So it’s a really exciting signing for us to make and we’ve got someone who can hopefully make a huge impact here.
“We’re pleased with the transfer activity we’ve been able to do so far this summer, working with the recruitment team.
“A lot of these moves have been many months in the making and so it’s great to see all that hard work coming to fruition."
Scully looks set to be followed out of the door by midfielder Tom Naylor.
Chesterfield are understood to be on the verge of completing a deal for the player, who turns 32 this month.
Naylor – who won League One with Latics in 2021/22 – was out of contract this summer, but had a 12-month extension triggered.
That may see Chesterfield having to pay a nominal fee for the services of Naylor, who had also been strongly linked with his hometown club Mansfield.