Trauma medical director Gudata Hinika at California Hospital said that Johnson arrived with a threatened airway and required extensive specialized surgery by an otolaryngologist.
The hospital put out at statement that said he was in "critical but stable condition. His post-surgical prognosis is good."
While it's unlikely that Johnson will be able to complete the season, doctors expect him to make a full recovery, Hinika said in the statement.
Johnson was bench-pressing with an assistant strength and conditioning coach spotting him when the accident occurred. The bar slipped out of Johnson's right hand and landed on his throat.
Head strength and conditioning coach Chris Carlisle, who was in the weight room at the time of the accident, said he has never witnessed such an accident, "I've seen players have the bar slip and fall onto their chest, but never in my 25 years of coaching have I heard of someone dropping a bar on their throat. We're fortunate he was being spotted."
Pete Carroll added: "I've never seen the guy take the whole thing like that and get hit in the neck."
The senior tailback from Compton has rushed for 157 yards on 32 carries this season and has a team-high five touchdowns.
Stafon Johnson celebrates his 6-yard TD run against Washington State. (Jaime Rodriguez Photo)
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