The 21-year-old joined for an undisclosed fee from Arsenal on Monday, penning a two-year deal with a club option of a further 12 months.
The right-back came through the ranks at the Emirates Stadium, featuring at all levels in the academy but failed to make a first-team outing under Mikel Arteta.
We spoke to freelance commentator Max Jones, who’s worked at Arsenal for eight years, to give us the lowdown on the Blues’ newest recruit.
Here’s what he had to say.
‘He’s a very switched on lad, he’s very keen to learn, very keen to succeed and you get the impression from around the academy at Arsenal that he’s a great listener, willing to put in the extra work off the pitch as well by making sure he’s in good condition in the gym.
‘On the pitch, he’s a manager's dream because he’s willing to play wherever he’s put. When he played for the under-18s and under-23s, he’ll chip in with a seven out of ten performance most weeks.
‘He’s very solid defensively, likes to get forward as well, although the best times I've seen him is when he’s been a bit more conservative at the back and is shoring up the defence.
‘He’s a fantastic dribbler and can dribble at pace as well but most importantly for Pompey, he’s defensively sound.
‘If Cowley wants to play three at the back or four at the back then Swanson can fit into those systems, whether that’s at right wing-back, right sided centre-back or even on the left.
‘He made 15 consecutive senior squads without making his debut. He was very unfortunate with where he plays positionally and that Arsenal weren’t in Europe and didn’t have a cup run. If they had been given more generous cup ties then I have no doubt he would’ve been given more minutes.
‘They really did rate him there, you don’t get into the Arsenal squad - and be on the bench - if you’re not rated.
‘He regularly trained with them, he was just very unfortunate not to get out on the pitch but he did have some very experienced players and internationals ahead of him.
‘The most important thing, Zak would’ve been listening to what Emil Smith-Rowe had to say about Danny Cowley from their time at Huddersfield.
‘For me, the other important thing is his squad number. If he goes straight in and is given the number two shirt that’s a huge confidence boost for him but equally he still has everything to prove.
‘I think he’s going to relish the challenge and I think he will be a really decent signing for Pompey.’