Pompey have been dealt a devastating blow to their Championship push after Regan Poole was ruled out for the season.
The outstanding defender’s 2023-24 campaign is at an end, after it was confirmed he tore his anterior cruciate ligament in the FA Cup defeat at Chesterfield.
Poole fell awkwardly after being nudged in the back by Will Grigg - and scan results have now confirmed the outlook is way worse than originally expected.
The 25-year-old has been arguably Pompey’s best player this season with Mousinho acknowledging it’s a big setback for his side.
He said: ‘Regan has torn his ACL unfortunately, so that’s him for the season.
‘It’s one of those things in football that can happen, there’s nothing you can do about it.
‘It’s a nudge in the back from Will Grigg and one of those things. I’m gutted for Regan.
‘We have to make sure we deal with it. If anyone can deal with a long spell out and making sure he’s fit and strong, it’s Regan.
‘These days ACL injuries, they’re not ideal but they aren’t the career threatening injuries they were in the 90s or early 2000s.
‘The surgery is excellent, they’re quick and in and out. I know that having had one myself and coming back in sparkling form obviously! The prognosis for him is good.
‘Of course it’s a blow. We don’t want to lose any player and the fewer injured the better.
‘Regan has probably been one of our players of the season, he’s been absolutely outstanding since he signed.’
Pompey are still digesting the news of Poole’s injury after the extent of the issue became apparent yesterday.
Sean Raggett replaced the Wales international against Charlton and appears the next in line to start at the back.
But with the likes of Ryley Towler to call upon, Mousinho feels he has options to replace the summer arrival from Lincoln.
He added: ‘Of course we’re disappointed. I’m not happy about the situation, but my message to the boys is I’m happy with the fact we have strength in depth.’