Kenny Jackett saluted the arrival of Tom Naylor's Championship nous.
The midfielder has agreed a three-year deal with Pompey and will arrive from Burton.
Naylor has picked up 66 second-tier games with the Brewers and was part of their side which won promotion from League One in 2015-16.
Jackett believes the 26-year-old will add combative qualities to his side as they aim for success next season.
He said 'It strengthens the spine of our side, while he also brings us recent Championship experience.
'Tom’s a ball-winner and I feel that he’ll complement the other talented players we already have at this club.
'He’s someone who can play in a variety of positions, although he’s primarily been brought in as a defensive midfielder.
'We do feel that the squad is being improved this summer and we’re getting to where we want to be.'