Seantrel Henderson left Cretin-Derham Hall in 2010 as one of the top-rated high school football players in the country.

But since arriving at Miami (Fla.) that fall, little has gone right for him. He was once considered to be a certain elite draft prospect, but suffered another blow to his reputation Monday when ESPN reported Henderson tested positive for marijuana at the NFL combine.

Now he might not get drafted at all.

Henderson was suspended three times at Miami for the same reason. At the Senior Bowl in January, he insisted he was putting those issues behind him.

"I just look to show that I'm a hard worker and I have great character," Henderson said. "I felt like I had some bad press in the media that made teams in the NFL think that I'm kind of a bad guy or a knucklehead. I just felt like I made a couple bad decisions, and I think that I deserve a chance to play in the NFL and that I'm a first-rounder."

ESPN also reported that Henderson quit halfway through his Pro Day workout last month because of dehydration. All of these red flags could prevent Henderson from being selected in the draft, only four years after a prep career that led Sports Illustrated to call him "probably the most polished lineman of the past decade."

During his senior season, Henderson led Cretin-Derham Hall to a Class 5A title and was ranked as the second-best recruit in the country, according to Rivals.com. The highest conference honor Henderson received during his four years at Miami was third-team All-ACC last season, when he started eight games at right tackle.

Henderson, at 6-7 and 331 pounds, carries the size to succeed in the NFL. But the promise he carried coming out of high school has taken a big hit, and teams must now decide quickly whether he's worth the risk.