The Scotland international, who has been out of action since the beginning of November with an ankle ligament injury, will travel to Fratton Park and, while he has no chance of starting the game, could be included among the substitutes.
Manager Tony Mowbray said: "It's good to have him back on the training ground. He's a senior player and it's good to hear his voice, and we just need to incorporate him back into the squad as quickly as we can.
"We have lacked some experienced footballers on the pitch. It has generally been a young group and the strikers have been the older players in the team.
"With total respect to the strikers, at times they can be looking after their own jobs, so it will be good somewhere down the line to have experienced players back who can help the players from the back and organise from behind rather than being up front."
Meanwhile, full-back Joe Bennett will play at Pompey wearing a protective lightweight cast after chipping a bone in his wrist.
Source: PA
Source: PA