Pompey have signed Nicky Shorey in a deal that will initially run until the end of the season.
The 32-year-old full-back was a free agent after leaving Bristol City last month.
He said: “I’ve played at Fratton Park many times before and there has always been a great atmosphere, so I am delighted to now be playing for the fans here.
“I’ll always remember the 7-4 defeat Reading suffered in the Premier League because I missed a penalty and it was an interesting day to say the least.
“You can never say anything for definite in football, but with people like Richie Barker and Steve Coppell – who I know really well – here then it will only be a matter of time before we get back to where we want to be.”
Blues boss Richie Barker added: “Nicky has trained with us for a couple of days and really enjoyed it.
“He’s an experienced player and Steve Coppell knows him inside-out, having worked with him for a number of years. That counts for a lot.
“He’s also keen to come to Pompey and be a part of where we want to go as a club.”
Shorey started his career at Leyton Orient before moving to Reading in 2001.
While with the Royals, he won promotion to the Premier League and earned two caps for England.
Shorey made a total of 296 appearances before moving to Aston Villa in 2008 and then West Brom two years later.
He returned to the Madejski Stadium for a second spell in 2012 before signing for Bristol City last summer.