If they don’t add him to the 90 man roster and place him on IR then he might actually qualify for an injury settlement. That would mean that the chiefs compensate him for the time he will miss and he becomes a free agent.
Not entirely sure with him being there on a tryout, though. Sadly, an entry level office worker makes more than an UDFA player who gets invited to rookie camp or an off-season tryout. Other than travel expenses and lodging I believe they get a small per diem and about 1000-1200/week before taxes.
I also wonder if he qualifies for the NFLPA medical insurance since he hadn’t been signed.