[Lizard]

In the calendar view, select your Sysadmin. Change their "Normal work week" to not contain any work time at all. Now switch to the "Work Schedule" for your sysadmin. For each week your sysadmin will be working on the project, draw back in the green bubbles for his work week. Now you can level the project and the work for the sysadmin will all be scheduled during the few weeks they have hours.