TAMPA, Fla. -- Hours after sending a gracious yet puzzling middle-of-the-night text message to a former college coach, police say Tennessee Titans receiver O.J. Murdock died in an apparent suicide.

Tampa police spokeswoman Andrea Davis said officers found Murdock about 8:30 a.m. inside his car with what appeared to be self-inflicted gunshot wounds. The car was parked in front of Middleton High School, where Murdock made a name for himself as a dynamic receiver and state champion sprinter in track and field.

Al McCray, assistant head coach/receivers at Fort Hays State, said when he woke up at his Kansas home on Monday he found a message on his cell phone from the player, thanking him for everything he had done for Murdock and his family. The athlete concluded the text with an apology that baffled McCray, who said he had known the 25-year-old since Murdock was in middle school.

"I spoke to him a week ago, and he was so excited about getting ready to go (to training camp). He was real happy about being able to help his mother out," McCray recalled. "You always like to hear kids who talk about that. It brings a smile to your face to hear a young man talk about 'Hey, I'm glad I'm able to help my mother out.' "

McCray was an assistant coach at Middleton when Murdock was there and later helped the player resume his college career after he was kicked off the team at South Carolina, where he was part of Steve Spurrier's first recruiting class.

"The hardest part about this is I got a text at 3:30 in the morning, where he said: 'Coach, I want to thank you for everything you've done for me and my family. It's greatly appreciated,' " McCray said. "At the end, he goes: 'I apologize.' And I don't know what he's talking about. I woke up, and I'm thinking he's apologizing because he texted me so early. ... I wish he had called instead."

Murdock, who signed with the Titans as an undrafted free agent in 2011 and spent all of last season on injured reserve, was taken to Tampa General, where he died.

The speedy receiver did not report to training camp over the weekend because of what the Titans said at the time was a personal issue. He last was with the team in June for mini-camp.

"We were concerned initially when O.J. didn't report on the 27th. But we were able to make contact with him and he assured us everything was OK and he would be in here on Sunday. He didn't make it on Sunday," Titans general manager Ruston Webster said.

"He didn't give us a lot of information. He was injured and ... when he left here probably wasn't quite ready to go, so we were probably a little more relaxed on him than normal," Webster added. "If he had come in here, he probably wouldn't have been ready to practice right away."

McCray said when he last spoke to Murdock, the receiver didn't provide any indication that something might troubling him. Titans coach Mike Munchak said the team didn't detect any signs, either.

"We didn't have any (hints). It's a phone call you never want to get," Munchak said. "It's something that as a head coach, you never think you'll have to stand in front of your team and give them that kind of news. I think everyone was shocked by it. We weren't aware that there were any issues going on."

Murdock signed with South Carolina out of high school but played in only four games, making one catch, after redshirting his first season. He was arrested for shoplifting at a Florida department store during the 2006 season and suspended.

"All of us here are saddened to hear of O.J.'s passing," Spurrier said. "Our condolences and prayers go out to his family and friends."

Murdock transferred to Pearl River Community College in Mississippi and then to Fort Hays State, where he helped transform one of the nation's least productive Division II offenses into one of the more prolific. As a senior in 2010, he had 60 catches for 1,290 yards and 12 touchdowns.

That earned him an invitation to the NFL scouting combine. After going undrafted, he was signed by the Titans last summer but spent the entire 2011 season on injured reserve after hurting his right Achilles early in training camp.

Murdock had been out of football for two years when McCray talked him into doing the necessary academic work necessary to get back into school and, hopefully, rekindle his career.

"O.J. came here without a visit, without anything. After I got him eligible, he could have gone anywhere he wanted in terms of Division II. A bunch of the top-rated Division II programs were recruiting him, but he was a loyal kid," McCray said. "He comes here, we go from being ranked 150th in total offense to No. 8 in the nation. We averaged 33 points a game where the year prior we were only averaging 8."

Three former NFL players -- Junior Seau, Ray Easterling and Dave Duerson -- each died of self-inflicted gunshot wounds in the past year and a half. Easterling and Duerson were found to have brain damage at the time of their deaths and their families are among those suing the league over the long-term effects of concussions. Brain tissue from Seau has been released by his family for study.

Murdock's name had not come up in the ongoing concussion debate, and Munchak said he had no knowledge of the player having a history of such injuries.

"There was nothing that I'm aware of at all with that," Munchak said.

McCray said Murdock's polite, humble disposition and infectious smile made him a big hit at Hays State, which was stunned by Monday's news.

"Our homecoming game his senior year, the fire marshal calls our athletic director to say: 'Listen, we can't allow any more people to come into this game, we're at capacity,' " McCray said. "Our A.D. was like. 'No, you're not. Let 'em in.' That's just the impact that kid had here."

"It's hard, it really is because he was such a good kid. He was lazy in the classroom in high school, and of course he messed up at South Carolina, but you're talking about a kid who was on his mom's couch for two years. ... He got the grades he needed and he came up here and he had one dream, one goal: 'I'm going to come out here and I'm going to play at a high level and I'll get to the National Football League.' And the kid did it. He did it."