ESPN's Field Yates has Thieneman as his No. 19 overall prospect and No. 2 safety behind Downs.
"Like the tight end class, there's good depth at safety," Yates wrote. "Thieneman stands atop as the best ball-hawking center fielder among them. He snagged six interceptions as a true freshman with Purdue in 2023 before two with the Ducks in 2025. He has a strong ability to diagnose plays and has great vision and hands that would grade out well if he were a receiver."
NFL lead draft writer Eric Edholm has Thieneman at No. 22 on his Top 100 list.
"Instinctive ball finder with good size and athleticism, as well as the ability to play high or low. Thieneman looks like a possible Day 1 starter to me," Edholm wrote.
What he had to say: "I just bring that hard worker, discipline demeanor, consistent," Thieneman said at the Combine. "I feel like I'm the same guy day in, day out."