With the NFL Draft only two days away, Antonio Callaway's draft stock just took a significant hit as yet another incident was added to his already lengthy list of off-the-field concerns. 

On Tuesday, ESPN's Adam Schefter reported that Callaway tested positive for marijuana -- a banned substance in the NFL -- at the combine in February. Callaway's new agent, according to Schefter and NFL Network's Ian Rapoport, confirmed that the sample came back diluted while Rapoport reported that Callaway claims the issue had to do with being over-hydrated. 

At Florida, Callaway caught 89 passes for 1,399 yards and seven touchdowns from 2015-16. At the combine, he posted the third-fastest 40-yard dash time (4.41) among all receivers. If prospects were judged solely on their ability to play football, Callaway would likely be regarded as a first-round pick.

But issues away from the field have called into question if he's worth a draft pick. Last week, NFL Network's Tom Pelissero reported that "one scout who has done a lot of work on Callaway predicted he would've been a top-20 pick if he were clean off the field" and that "an AFC scout said Callaway admitted in a combine interview to smoking marijuana about six weeks earlier."

The Miami Herald's Jordan McPherson recently recounted Callaway's transgressions before the news of his diluted drug test surfaced. Here's what he wrote:

He was one of nine Florida players suspended before the 2017 season opener while being investigated for credit card fraud. He accepted a pre-trial intervention, which will scrub the felony charges from his record.

A year earlier, he faced sexual assault allegations and a subsequent Title IX hearing. Callaway was found "not responsible" in that hearing — which was overseen by a judge who also happened to be a booster for the Florida athletics program. 

Callaway was also cited in May for marijuana possession during a traffic stop while in the car with a man who has a lengthy rap sheet. He pleaded no contest to possession of paraphernalia and accepted a fine.

"I'm a great person. I'm not this bad person that the media portrays. I mean, I can't stress it enough," he said at the combine, per the Miami Herald. "I just gotta … let my actions speak for me."