But he had no idea how things were actually going to go, no idea how his body was going to react to being put through the grind once again.
Nelson's gut feelings were correct as he had a solid pro day in Norman on Wednesday. Nelson is trying to get back into scout's minds after disappearing from NFL Draft talk following his season-ending injury.
Nelson partially tore his pectoral muscle in October and missed the final eight games of OU's season. And once he was denied a medical hardship for a fifth year, it was full speed ahead for Nelson in concentrating on the draft.
That first step was Wednesday.
"I feel like I'm 100 percent," Nelson said. "I'm back where I need to be, back to where I felt at the beginning of the season. It's a great feeling."
Nelson was timed at 4.64 seconds in the 40-yard dash, but it wasn't his speed that caught him by surprise. Instead it was his strength. Nelson did 23 reps at 225 pounds.
"I didn't expect to get that much there," Nelson said. "It felt good, though, felt really fluid. The other thing was position drills. I'm playing linebacker and doing DB drills. It's something I had never done before. It felt pretty good. I was pretty pleased."
Nelson had 27 tackles, including three for loss and an interception return for a touchdown in his senior season before the injury cut his career short.
He measured in at 6-foot ¾ inches and at 230 pounds and also posted a 33-inch vertical jump. As of this time he has not been given any indication of what might happen in May when the draft rolls around.
The only thing he knows for sure is he'll be ready.
"I'm just going to put it in God's hands and go where my agent tells me to go," Nelson said. "Whatever it takes is what I'm going to do."