My guess is that it will be a mix of both, fatigued and rested players.
Their whole midfield consisting of Simoes, Johansson & Mantalos didn't changed in the last 4 matches. Skasmenoi einai. Moreover, Aravidis played 5 matches straight. If they play against us too, they will collapse. Besides Buonanotte, there is no good midfielder on their bench.
Vargas, as their best scorer this season, will miss the game. Same goes for Djebbour. This means that we probably have to deal with a rested Barbosa and Peckhart, maybe Platellas too, regarding their offense.
Their defense didn't changed (with one exception) the last 5 matches. They are probably exhausted too.
As I'm seeing this, they will have some trouble in their midfield and defense. Their offense on the other hand is rested, with the exception of Aravidis.