Danny Cowley revealed Pompey are ready to strengthen their skipper’s reappearance from a hip injury.
Robertson has been out since September, after quickly establishing himself as a meaningful part of his new side following his summer arrival from Rotherham.
The 28-year-old was yesterday holding talks with the surgeon who reattached a muscle, which had come away from the tendon in his quad.
For the latest Pompey news direct to your inbox sign up for our free newsletter
And if they progressed well, Robertson will be able to take his rehabilitation work outside and begin doing some ball work.
Cowley is hopeful of a return before the new year for the Scot, but stressed Pompey will err on the side of caution with a player of his importance.
He said: ‘Clark truly had a speed call with his surgeon yesterday.
‘We were hoping that would give him the go-ahead to do some outdoor work.
‘We’re hoping he could be back 12-14 weeks post injury. We’re now week eight or nine.
‘We’re getting there.
‘I’m hoping (he returns) before January, but I’m thinking we may have to be careful with him.
‘He’s such a big player for us, when he comes back we want him to stay fit. He’s a top player, top player.
‘It will be some work outside, running, change of direction, some quickness drills and ball work.
‘We’re hopeful we will be able to put our foot on the gas.’
Designed with Pompey fans in mind
Get unlimited access to all The News’ sports coverage without the need for a complete subscription. Play-by-plays of every match, in-thoroughness examination, live blogs and exclusive interviews starting from just £2 per month; that’s just 50p per week – click HERE to subscribe.
Click: See details