Goodson lay prone on the turf for about 15 minutes Tuesday as Raiders teammates and trainers rushed over. Paramedics and firefighters arrived shortly thereafter, and the 25-year-old running back appeared to move his legs and arms.
"He did have feeling in his extremities, which is good news," Allen added, according to CBSSports.com.
"That's hard when you see one of your teammate go down like that," the coach said.
Wheeler, projected as a starting outside linebacker for the Raiders, was visibly shaken and was still upset when talking to reporters after practice.
"I texted him already and told him that I'm praying for him, that I'm sorry and I didn't mean to do it," Wheeler said. "I thought he was going to get up. I didn't think he was that bad off until he said ... that he couldn't get up. That's when I knew he was pretty bad.
"It was just a bang-bang play. I'm just going to pray for him. I didn't mean to do it. I didn't mean to hurt him."
"It's scary when that happens to anybody," Palmer said. "We're all praying and hoping it isn't serious."
Practice continued while workers removed Goodson's facemask but left the rest of his helmet intact. Goodson was strapped to a backboard before being loaded into an ambulance.
The Associated Press contributed to this report.