Miami Dolphins defensive tackle Kendrick Norton has had his left arm amputated after he was involved in a multi-car crash in the Miami area early on Thursday morning.
Norton's agent Malki Kawa confirmed the severity of the situation in a Twitter post on Thursday.
He said: "With sadness, I can confirm that Kendrick Norton was in a car accident last night and suffered multiple injuries, including the amputation of his arm.
"We ask that you continue to pray for him.
"His family also asks that the public respect Kendrick's privacy."
The former University of Miami stand-out was listed in critical condition at a Miami hospital, but his injuries are not believed to be life-threatening.
The impact of the crash was so severe Norton's arm had to be amputated by paramedics at the scene, according to a report in the South Florida Sun Sentinel.
"We were made aware this morning of a serious car accident involving Kendrick Norton," the Dolphins said in a post to the team's Twitter account on Thursday.
"Our thoughts and prayers are with Kendrick and his family during this time."
Norton, who turned 22 on June 7, was signed off the Carolina Panthers' practice squad last year and was expected to compete for a spot on the Dolphins' 53-man roster this summer.
The 6ft 3in, 314-pound defensive lineman had 84 tackles in three seasons at Miami in college, including five sacks.
Norton, who has not played in an NFL game, was a seventh-round draft pick by the Panthers in 2018.