Liam Vincent went closest to breaking the deadlock with a shot which struck the inside of the far post, while Anthony Scully had a goal ruled out for offside.
Yet the opening 45 minutes finished goalless ahead of a scheduled 11 changes at half-time as Mousinho utilised 22 members of his playing squad.
There were some encouraging displays and here are our player ratings for the first half...
. Portsmouth goalkeeper Will Norris during the Pre-Season Friendly match between Bognor Regis Town and Portsmouth at Nyewood Lane, Bognor, United Kingdom on 11 July 2023.
Pompey keeper Will Norris warming up ahead of tonight's friendly at the Rocks. Picture: Jason Brown/ProSportsImages Photo: Jason Brown
. Will Norris - 7
Came out of the box well to take possession of the ball on one occasion and there was one lovely left-footed pass to the left which just eluded Ogilvie. Yet not called upon to save anything. Photo: Portsmouth FC
. Josh Dockerill - 7
A solid showing at right-back. Did little wrong and used the ball effectively when called upon. Clearly enjoying stepping up to the first-team environment this pre-season. Photo: Jason Brown
. Sean Raggett - 7
Rarely troubled and fully in control, as you’d expect. Kept things simple and a solid display all-round. Photo: Jason Brown
1. Will Norris - 7
Came out of the box well to take possession of the ball on one occasion and there was one lovely left-footed pass to the left which just eluded Ogilvie. Yet not called upon to save anything. Photo: Portsmouth FC
2. Josh Dockerill - 7
A solid showing at right-back. Did little wrong and used the ball effectively when called upon. Clearly enjoying stepping up to the first-team environment this pre-season. Photo: Jason Brown
3. Sean Raggett - 7
Rarely troubled and fully in control, as you’d expect. Kept things simple and a solid display all-round. Photo: Jason Brown
4. Ryley Towler - 7
Produced a left-footed shot from 30 yards in the 13th minute which the keeper couldn’t hold, while was lucky to escape receiving a booking after a foul on Pattenden. Another good game, though. Photo: Sarah Standing