Hayden Mullins is expected to be fit to take on former club West Ham this weekend.
The 32-year-old picked up a groin injury in Pompey’s last outing against Cardiff.
That ruled him out of the Real Betis friendly and all of last week’s Spanish training sessions.
But Mullins returned to training on Monday with no reaction.
That puts the influential midfielder in the frame for an Upton Park reunion.
He spent six seasons there, playing 213 games before moving to Fratton Park in January 2009.
And his return to fitness is a boost to Cotterill.
The Blues boss said: ‘Hayden should be okay.
‘He hurt his groin against Cardiff and was unable to train at all last week.
‘We couldn’t get him back into training until Monday.
‘Hopefully, there will be no ill effects from that. There haven’t been so far.
‘I think he will be okay for West Ham.’
Also given green lights are Erik Huseklepp, Hermann Hreidarsson and Marko Futacs following their international duty.
Cotterill has still to speak to Liam Lawrence, although the midfielder didn’t get any game time for the Republic of Ireland in Russia.
Tal Ben Haim should also be fine despite a back scare.
He added: ‘Tal returned from international duty with a bit of a sore back.
‘I have not spoken to Liam yet but he did not play.
‘I think everybody will be okay, though.
‘I should have a full squad to choose from.’