Christian Oxlade-Chamberlain will miss the remainder of Pompey’s season.
The versatile player sustained a broken leg during shooting practice in training on Monday.
He is going to be back. It’s a broken leg, which is not good, but he’ll be backJoe Gallen
Assistant boss Joe Gallen described the incident as a ‘freak’ – with nobody near the 19-year-old at the time.
As a consequence, Oxlade-Chamberlain will require an operation before commencing his recovery.
It’s already a tense time for the youngster, who is out of contract at Fratton Park this summer.
And Gallen has pledged the club will do all they can to aid Oxlade-Chamberlain’s recovery.
He said: ‘It was very innocuous. Christian took a shot and his foot got stuck in the ground. In his words, he heard a crack.
‘The scan has proven there is a fracture to his leg, which will obviously keep him out for the rest of the season and he is due to have an operation.
‘It was strange. He was just on his own taking a shot. No-one could quite understand why he heard a crack because nobody was near him.
‘I do feel for him, it was a completely freak incident – and it’s bad timing.
‘I believe Christian’s contract is up in the summer, so timing-wise it is also not good.
‘He’s a fantastic lad who has been out on loan a little bit but he is young and it’s not going to hinder his career too much.
‘He is going to be back. It’s a broken leg, which is not good but he’ll be back.
‘Unfortunately these things do happen but he will be back and will get the best care and attention we’ve got in order for him to recover.’
Oxlade-Chamberlain has spent time on loan at Poole Town and Oxford City this season to aid his development.
However, he was recalled from non-league football in March with Pompey squad numbers devastated by injury.
Earlier this summer he was an unused substitute in four of the Blues’ matches, including three successive League One fixtures in October.
Having emerged through the Fratton Park ranks, Oxlade-Chamberlain’s deal was extended for another 12 months last summer.
That is now scheduled to end at the season’s finale, with Pompey weighing up whether to extend it.
Serving in midfield or at right-back, he has been a regular for the club’s reserve team this term.