Defoe, who turns 26 next week, is one of six former Tottenham players at Fratton Park and admits: "Of course I'm looking forward to this game.
"It's a special one for everyone but obviously a special one for, me. I'd be a liar if I said it wasn't.
"I thought I was going to play against Spurs last season but then got a phone call the day before the game telling me I couldn't."
Pompey initially signed Defoe on loan to beat the transfer deadline after selling top scorer Benjani to Manchester City.
The loan element - even though it only lasted a few days - meant that under Premier League rules he was barred from facing his former club in the same season.
It came as a nasty surprise and Defoe, who was also ineligible for Pompey's glorious FA Cup run having already played for Spurs, recalled: "It was a massive blow because it's always nice to play against your old team. All week I'd been looking forward to it.
"Now finally it looks like I've got my opportunity and I've always thought if you get it you've got to perform and that's what I'm aiming to do.
"Don't get me wrong I loved the years I had there, made a lot of friends. It's a great club.
"But I didn't feel I had the opportunities I deserved there. A lot of times when I played and scored the next game I'd be back sitting on the bench again and it was difficult for me to understand.
"I kept my head down a for a long while, kept on working hard, but I knew I'd have to move on.
"I don't know what's gone on since at Spurs. They've sold some world-class players but they've also bought some as well and they are still a really good side despite the early results.
"But people turn up to see top players like Dimitar Berbatov and Robbie Keane and although I wasn't surprised when Berba went, I was a bit when I heard Robbie was going to Liverpool."
Defoe added: "All players want to feel appreciated, it's a massive thing. There's nothing better than when you want to go out there and do well for the manager and everybody else involved and that's me now.
"I got off to a good start at Portsmouth and the more goals you score the more confident you get - and I'm still playing with quality players."