The midfielder last week returned from Munich following surgery to resolve long-standing pain in his abdomen.
The procedure is the latest attempt at returning Morris to first-team action following a wretched time with injury since the end of June.
Kenny Jackett admits the 23-year-old is expected to return to working outside within a fortnight, yet is unable to pinpoint potential availability.
The Blues remain confident Morris will be back playing before the end of December.
Denver Hume: Portsmouth's expensive forgotten man and why former Sunderland defender really could be one for the future
'We wanted to show him a bit of love' - Portsmouth-based Spurs fans' terrific gesture to ensure Dane Scarlett feels at home on the south-coast
League One latest: Portsmouth linked duo set for Oxford United and Lincoln moves, Southampton prospect joins Blues rivals as Ipswich land former Blackpool and Derby veteran
'Real driving force... lion-hearted display... classy presence' - Neil Allen's Portsmouth ratings from 3-0 Carabao Cup win at Cardiff
'We’ve got a real problem': Portsmouth boss reveals headache after career first at Cardiff
Anything more precise is presently not being pencilled in until it can be gauged whether he is pain free when kicking a ball.
Jackett said: ‘Bryn came back from Germany last Wednesday and hopefully that cures his problems.
‘He’s had a frustrating time and the nature of an abdominal injury is it’s a sensitive area, which unfortunately has resulted in an operation.
‘Hopefully this once and for all can cure it and he can get back out on grass and, most importantly, stay there because many times he has tried to come back.
‘He’s frustrated as well because he is a hard-working guy.
‘With Bryn, there is not necessarily a timescale on it, we will certainly give him 1-2 weeks to see how he settles down.
‘Then he will start building up, getting him outside and see how he is.
‘I don’t think it’s a particular area where you can tolerate a lot of pain. Maybe an ankle you can get through, warmed up and get moving, but not the abdominal area.
‘When you are checking and turning, striking footballs, or maybe going right through a ball or turning at full pace, it can be painful and definitely inhibit you.
‘The plan with him is 1-2 weeks, then he will be outside and doing gradual build-up, hopefully with no further problems.’
The Blues had hoped to avoid an operation for Morris, instead relying on rest and rehabilitation.
Ultimately, though, Jackett insists there was no choice, prompting the former Shrewsbury man to fly to Germany for treatment.
The Blues’ boss added: ‘We have really tried everything and, as it should be, the operation is a last resort.’