Cushing is still among the nominees in the revote. All ballots in the revote are due by early Wednesday afternoon.
Cushing has been suspended for the first four games in 2010 for violating the league's anti-doping policy. He was tested last September, league sources told ESPN NFL Insider Adam Schefter.
After being alerted of the positive test, Cushing was tested randomly numerous times throughout the season and never tested positive again, a source familiar with the case told Schefter.
Cushing said he took the substance during September, the first month of the 2009 schedule. Although Cushing said his positive test was not for a steroid-related substance, the positive test was for something that was considered performance enhancing. Cushing appealed the decision and lost that appeal.
Cushing's test was positive for slightly elevated levels of hCG, the source familiar with the case told Schefter. The level that he tested positive for was so low that it would not have been considered a positive test even a year ago.
hCG (human chorionic gonadotropin) is a banned substance that is widely used to stimulate the body's testosterone production after an athlete uses anabolic steroids.
If a player has a medical need for it he can request a therapeutic use exemption, but if he had an exemption, Cushing wouldn't have been suspended.
One person familiar with testing procedures told Schefter that hCG is contained in seminal fluid and that slightly elevated levels can be discovered in the event that a test occurs soon after ejaculation.
Cushing took and passed a lie-detector test to prove he was not guilty of taking a performance-enhancing drug, but his four-game suspension still stands, a league source told Schefter.
Cushing was a runaway winner for the rookie award in balloting by a nationwide panel of 50 sportswriters and broadcasters who cover the league. He received 39 votes, easily beating Buffalo safety Jairus Byrd, who had six.
"This is the first time we've encountered an issue like this," said Lou Ferrara, AP's managing editor for sports and entertainment. "Because these awards are based on on-field performance, we consider it necessary to review the matter and allow for a revote, especially after concerns were raised by many of our voters."
Houston Chronicle columnist John McClain wrote Tuesday that he voted for Cushing to win the award again.
"Why? Because a lot of players have won AP awards after being suspended," he wrote.
Texans owner Robert McNair on Monday criticized the suspension and appeal process that he said doesn't provide enough information to the team.
"The club is left completely out of the loop on that," McNair said. "We're not even notified, it's the league and the player and the players' union. All we know is what's been announced at this point in time."
McNair said Monday that the Texans were aware that Cushing had "an issue" with the NFL last season but didn't know the details.
"Brian had mentioned that he had an issue there, but we don't know what any of the details are, we don't know what doctors he may have consulted with, we don't know what evidence that the league might have had ... which is a very bad position to be in because we're the guy that's got the investment in the player. The league doesn't have any money invested in the player, the union doesn't have any money invested in the player, and yet they get the information and we don't.
"So it's a sensitive area because it is sort of like medical information and there's confidentiality and this sort of thing. But I think it's something that needs to be addressed in the next collective bargaining agreement."
The NFL did not immediately comment on McNair's statement.
Although he is suspended for the Texans' first four games (Houston's opponents: Indianapolis, Washington, Dallas and Oakland), Cushing can participate in preseason practices and games.
Cushing will not be eligible for next season's Pro Bowl -- he made the AFC team last January, but did not play, citing several injuries -- or any NFL-sponsored awards.
"In the year a player is notified of and serves his suspension, he is ineligible for selection to the Pro Bowl or to receive any other honors or awards from the league or the NFL Players Association," NFL spokesman Michael Signora said Monday.
That includes player of the week and player of the month awards, the Walter Payton NFL Man of the Year Award and the Super Bowl most valuable player award.
Cushing, the 15th overall pick in last year's draft out of Southern California, had 133 tackles in 2009. The Texans finished 9-7 last season for their first winning record thanks in part to the improvement of a young defense that features Cushing, star middle linebacker DeMeco Ryans and 2006 top overall pick Mario Williams.
Veteran Kevin Bentley, who appeared in each game for Houston last season but never started, is Cushing's backup at outside linebacker.
However, the Texans are likely to cover for Cushing's absence by moving Zac Diles into Cushing's spot and inserting Xavier Adibi into the spot vacated by Diles.
Cushing was hounded by rumors of performance-enhancing drug use before he became a pro, but the Texans were undeterred. They said then they found no truth to those rumors in their draft preparations.
"Brian, what he has said, is he's been taking the same supplements ... for the last 10 or 15 years and he's been checked umpteen times and it hadn't shown up to be any kind of problem," McNair said. "So what happened, I don't know. He doesn't know at this point in time.
"The fact [is] that he didn't think he would get the suspension, but that's the way it is at this point in time and we accept it and we need to move on."
Cushing's case differs from San Diego's Shawne Merriman, who won the 2005 defensive rookie award, then tested positive in the 2006 offseason for steroids contained in a supplement. Carolina's Julius Peppers won the 2002 award even though he had already been suspended for the final four games of the season for violating the league's drug policy -- he used a dietary supplement that contained a banned substance.
Information from ESPN NFL Insider Adam Schefter, ESPN's T.J. Quinn, ESPN.com's Paul Kuharsky and The Associated Press was used in this report.