Gareth Evans is in contention to feature for Pompey against Oxford on Sunday.
And the midfielder will be joined in the Blues reckoning by Nathan Thompson, who has served the final game of his four-match suspension.
Evans has been out with a hamstring injury since scoring in the 3-1 defeat at Southend on February 17.
He suffered a recurrence of the problem after netting in the 36th minute at Roots Hall - forcing him to miss the Blues' past four matches.
Thompson was sent off midway through the second half against the Shrimpers and has subsequently completed his four-match ban.
Both will train with the first team this week in preparation for Sunday's televised game against the U's.
Speaking at his Monday press conference today, manager Kenny Jackett said: 'The likes of Thompson and Evans, they're senior players, they're established at the club, they're confident, they need to come back into the group.
'We need those two this week, and then further the likes of Hawkins and O'Keefe coming back.
'We need all of those guys for me to get the best out of the squad that we have.'