Glad to see he's racing. The 5000m is a tough event at the international level. All of the guys below I could imagine beating Rupp on a good day:
Choge
Koech
Lagat
Lalang
Longosiwa
Rop
Soi
However, I expect probably a third of the runners to have an off day, which rarely seems to strike Rupp, so I'll say he'll be 5th or 6th. I'll give him the benefit of the doubt and go with 5th.