Pompey travel to Peterborough tomorrow with the stakes high in the League One promotion showdown.
Mousinho has fitness and injury issues to contend with, as he's tasked with blunting the division's more potent attacking force.
And then there is the big talking point of who starts up front out of Kusini Yengi and Colby Bishop?
What does Mousinho do in terms of formation, too, after switching to a back three against Burton on Tuesday night?
Here's how we think the Pompey boss will go against Darren Ferguson's side.
9. RW Abu Kamara
Might not be able to 'sign him up' but the Norwich's loanee has a big part to play over these final eight games. | National World
10. ACM Myles Peart-Harris
This is the time we need to see Peart-Harris come to the fore. Form has fluctuated after man-of-the-match debut, but it's clear the quality is there. Pompey need to see it at London Road on the big stage. | National World
11. LW Paddy Lane
Time for Lane to come to the fore, after no goals in four. It may be that his work against the ball is more important on this occasion, with Peterborough's major threat in wide areas. | National World
12. CF Kusini Yengi
It's Pompey's million dollar question and the clamour among fans appears to be for Yengi to continue, although that is no slight on Bishop at all. The Aussie is the man in form with the pace to worry the home side and potentially stop Peterborough's ball-playing defenders stepping out. It will likely be a shared shift, but the in-form striker deserves the nod. | Jason Brown/ProSportsImages