Northwestern football players and coaches expressed their surprise Thursday that former NU defensive tackle Luis Castillo tested positive for androstenedione at February’s NFL draft combine.

“Yeah, I was surprised,” said senior defensive tackle Barry Cofield. “You also have to look at a guy like Lou, the kind of character he has. He’s an Academic All-American, things like that … He took some bad advice from some people that he shouldn’t have trusted and made a mistake.”

While the players and coaches were surprised, they remained adamant in supporting Castillo.

Coach Randy Walker issued a statement at practice that echoed the thoughts he expressed in a letter he sent to NFL teams along with Castillo’s letter.

“I’m standing behind Luis with my strongest endorsement,” Walker said. “He’s been a great kid, he’s come through so much as a football player here, and I have no doubt, and I’ve shared that with a number of general managers and coaches, I have no doubt about his quality of character or the kind of person he is.

“He made a mistake. He’s been forthright and honest about that mistake, and I know he will make the situation right in the long term.”

Castillo never tested positive for steroids while at NU and said in his letter that he used the steroids as a “short cut” because he was frustrated with his recovery from an elbow injury, according to ESPN.com.

In his statement, Walker reiterated his stance on NU’s drug testing policy.

“I’m proud of the record we’ve had here at Northwestern,” Walker said. “We’ve never had an athlete test positive for performance-enhancing drugs. I think my stance and beliefs on that issue are very clear.”

Despite testing positive for andro, ESPN.com reported that Castillo is still expected to go in the late-first to early-second round of the draft.

ESPN’s Chris Mortensen said that while there is speculation that Castillo’s draft prospects weren’t hurt, Castillo will be more closely scrutinized.

Mortensen also said the positive test will cast a shadow over Castillo for the beginning of his career.

“On draft day when he’s drafted, it’s going to be the thing we talk about before we get on to the positive stuff about his playing,” he said. “When he’s doing his thing with the team’s media that drafts him, it’s going to dominate that. When he has his first good preseason game and regular season game it’s going to be more mentioned in passing than anything else.

“It’s always going to be kind of something that carries with him. But it’s something that he’s going to have to fight through and live through.”

Former teammates endorsed Castillo’s character and said they expect him to be able to move forward from this incident and have a successful NFL career.

NU senior quarterback Brett Basanez said he believes Castillo will be able to recover from this early setback.

“He’s ready for the consequences and he’s looking forward, not back,” Basanez said. “The only thing (the positive steroid test) will affect is the now. As soon as this thing kind of blows over, he’ll be able to kind of regain this trust from everyone and show everyone it was a one-time thing and show everyone he’s legit.”

Reach Paul Tenorio at [email protected].