The winger is sidelined for up to two-and-a-half weeks following the calf injury sustained against Scunthorpe.
He will now miss Saturday’s trip to Shrewsbury, while is expected to be absent from the Checkatrade Trophy final against Sunderland.
According to Kenny Jackett, however, the Birmingham loanee has no intention of surrendering his Wembley involvement.
And Solomon-Otabor is determined to return to action quicker than anticipated.
Pompey’s boss said: ‘Viv has a calf injury, it’s the lower calf, just above his Achilles, at a time when he had been showing a lot of ability,
‘Certainly he’s missing this weekend – and I think he has a lot to do to make Wembley.
‘My assessment of the situation is the week after that (Wycombe) is a reasonable, balanced target.
‘He’s a good player and frustrated with it, but a very positive lad.
‘Viv wouldn't rule anything out in terms of next week (Wembley), he’s a very, very positive lad, similar to Ronan.
‘He is pushing everything to make sure he gets there, as any player would.’
Another facing Wembley heartbreak is Dion Donohue, currently sidelined with a groin problem.
The problem flared up during Tuesday’s friendly with the Royal Navy, the left-sided player forced off before half-time in the 3-1 win.
There is encouraging news on Andy Cannon and Bryn Morris, however.
The January transfer window recruits are expected back in training in the middle of next week, although won’t be ready for Wembley.
Jackett added: ‘Dion is a similar timeframe to Viv.
‘There is a tear in his groin, he is not doing much for 2-3 weeks and looks doubtful for Wembley at the moment.
‘To be fair, there are other players, we are okay with that, other clubs have injuries, that’s no problem, we have a good squad.
‘It’s unfortunate for those lads, but for us it represents opportunities for other people.
‘Morris and Cannon will be training in the middle of next week. They won’t be considered for Wembley, but will be somewhere near the Wycombe game.’