Pompey have slipped to 19th in the Championship after Tuesday's last-gasp defeat by Peterborough was followed by a 1-0 reverse at Leeds on Saturday.
Cotterill can at least welcome Luke Varney back from suspension after the international break, while fellow striker Dave Kitson should be fit again.
"We would have liked to change things around a bit more - it would have been great for us to have someone like Luke Varney available," he said.
"We've had three big games in the last week and, in the first half, it looked like we struggled to get going. We could easily have got the three points we deserved against Peterborough, so it's been a cruel week.
"During the international break we've got to have a look back over this phase, then put it behind us and look ahead to the next game."