David Norris could make a surprise return to the Pompey ranks against Leeds.
The former Ipswich midfielder has been missing since the 1-0 defeat to West Ham when he was shown a straight red card for a reckless lunge.
After carrying a hernia problem for several months, Blues boss Michael Appleton sanctioned the operation to get him back to full fitness after his three-match suspension.
Norris revealed earlier this week he was on course for a return against Middlesbrough next weekend.
But his recovery has impressed Appleton, who has not ruled out a place on the bench for Norris tomorrow.
With Joel Ward recovering from a gash he suffered at Barnsley last week and Greg Halford expected to be back in training today – the Pompey squad is beginning to look more healthy.
Appleton said: ‘From last week, we’ve lost Dave Kitson for one game and obviously Erik (Huseklepp).
‘There’s an outside chance Greg Halford will train today, which would give us a boost.
‘And there’s a chance Joel could be in training having not trained all week and that will give us a boost as well.
‘We’ve also got the arrival of Scott Allan – although he hasn’t played a Championship game – and there’s an outside possibility David Norris might be available.’
While Pompey were able to name only three substitutes last weekend, Appleton has warned the bench could be lacking in numbers again with several others still missing through injury.
He said: ‘Who knows how many we will have? It will be very similar to last weekend.
‘Are we going to fill our bench? Who knows?’