Kenny Jackett has conceded Stuart O’Keefe’s Pompey injury record is threatening a permanent deal.
The combative midfielder was restricted to just 20 starts during a season-long loan from Cardiff.
I always knew with Stuart that when he came back the season would run out on him and it didKenny Jackett
An injury-hampered stay consisted of three-and-half months on the sidelines through groin issues.
O’Keefe returned for the final month of the campaign, featuring in the remaining six matches.
The Blues possess an option on the 27-year-old and Jackett has been impressed with his contribution.
But Pompey’s boss is wary about recruiting a player with ‘frustrating’ availability during his Fratton Park stay.
He said: ‘With Stuart, his time here been frustrated by injury. He missed three-and-a-half months, which is a big chunk.
‘I thought he brought experience and some good decision making in his final match against Peterborough, but it’s hard to really judge him on that particular game.
‘He’s got good experience, has outstanding character, it’s just there has been some frustration with injuries.
‘When signing players, sometimes you take a chance, but generally you need a robust, fit squad.
‘That is particularly important once the cold weather hits. The training ground may be wet and you are trying to train at a good tempo.
‘You cannot not train, you have to work, so you do need a robust squad.
‘Stuart has had some good spells, but I felt even when he was playing before his injury he was struggling slightly with things. You could see he obviously felt it.
‘I always knew with Stuart that when he came back the season would run out on him – and it did. The season ran out on him unfortunately.
‘It can’t be helped. I like him as an individual, but the year has been hampered by injuries.’
O’Keefe is contracted at Cardiff until the summer of 2019, yet is not part of Neil Warnock’s plans.
The Bluebirds are back in the Premier League next term and will seek to offload the former Crystal Palace man.
During his Fratton loan, O’Keefe made 25 appearances and scored twice. He impressed with his work-rate and positive attitude around the club.
Now Jackett must decide whether to bring him back to the south coast.
He added: ‘He’s a good character who has given everything he has got this year.
‘Against Peterborough he played in front of the back four and you probably do need somebody of that profile doing that. Danny Rose could do that as well – they are the lads that have been in there.
‘We’ll see what happens, he is a Cardiff player and has a Cardiff contract. They have just gone up to the Premier League, so I don’t really know what the future brings for him.
‘He has to go back and talk to Cardiff and see where he’s at first.’