Spurs Academy graduate Andy Barcham is the latest player to join Pompey as they continue to rebuild for next season in Division Two.
The 26-year-old has signed a three-year deal with the Fratton Park club and will officially join the Blues when his contract with Scunthorpe expires on July 1.
He scored 11 goals in 84 appearances for Scunthorpe after arriving at Glanford Park in the summer of 2011.
“It wasn’t really a big decision to make what with the size of the club and stadium and the terrific fanbase,” said Barcham after completing the move.
He added: “When I was here with Scunthorpe last season there was no evidence whatsoever that the club were having any problems.
“The fans still stood up, made a lot of noise and were proud of their team. That’s an unbelievable advantage when you’re out on the pitch.”
Pompey boss Guy Whittingham said: “We didn’t really have any out-and-out wide players in the team last season and I think it was important we got at least one in.
“Andy can give us a bit of excitement on the wing and offers us that touch of creativity that could prove to be the difference.
Barcham signed his first professional contract at Spurs in 2005. He had loan spells at Leyton Orient and Gillingham before heading to Priestfield on a permanent deal in 2009.
He scored 23 goals in 115 games for the Kent side before heading north to sign for Scunthorpe.