If you're looking for a weekly log of how many minutes each player has played at which position, they already have that. When you set your next game there's a "weekly statistic" (something like that) link which lists these numbers.
I know this weekly statistic. But how is it about the games two weeks ago? Or other example: if you look into that weekly statistik right now - how long played each player on saturday and how long yesterday on which position?
There is no possibiliy to check this right now. I would like to have this feature.