The Blues have been held to frustrating goalless draws with Shrewsbury and Rochdale in their opening games of the campaign.
Kenny Jackett now has to ponder his starting line-up to deliver three points against the Latics.
Here's how we think the Blues could line-up...
9. Attacking-midfield - Andy Cannon
Another position that Kenny Jackett will have to ponder. A lot will depend on whether Michael Jacobs is fit enough to start, but the Pompey boss may be prepared to give Cannon another run-out. Photo: Joe Pepler
10. Left-wing - Ronan Curtis
Has been declared fit enough to start after picturing himself wearing a protective boot earlier this week. Photo: Joe Pepler
11. Striker - John Marquis
Was guilty of missing two big chances at Rochdale but will stick one away if he keeps getting the chances. Photo: Joe Pepler
12. Sub 1 - Duncan Turnbull
Continues on the bench with Alex Bass injured. Photo: Joe Pepler