Justine Hunt / Redux Pictures file

Patriots quarterback Tom Brady and actress Bridget Moynahan dated for three years before breaking up late last year.

As they have become more in demand, they seem to be more demanding. “Even the PR employees of teams try to shield the players from you now, rather than be your liaison to them,” said Mike Downey, columnist for the Chicago Tribune who has been a newspaperman since 1966. “So do the agents. A guy representing Roger Clemens wouldn’t put him on the phone to me just to talk about Roger’s 40^th birthday and how he stayed so fit. The agent told me, ‘If I do it for you, I’ll have to do it for everyone.’

“A PR agency representing Clemens had ASKED me if I’d be willing to interview Roger. And then his own agent wouldn’t let me.”

Levin said one major reason athletes covet celebrity, and are careful how they’re presented in public, comes down to profit.

“It translates into money,” he explained. “For a lot of sports guys, if they can prove that they’ve reached a certain level of celebrity, it helps them with endorsements to say, ‘I’m on TMZ three times a week.’ They use us the way we use them.”

Nowadays, the phenomenon seems to be extending past professional athletes and down to colleges and even high schools. After all, Kobe Bryant made waves when he took pop star Brandy to his senior prom. On letter-of-intent signing day, college football recruits draw live coverage from cable news shows for their decisions.

Scott Wolf has covered USC football for the Los Angeles Daily News since 1996. For most of those years the Trojans were mediocre to poor. But since Pete Carroll arrived in 2001, a new era has dawned — not just on the field, but on the sidelines during games and in nightclubs around Hollywood.

“They became so high-profile that anything they did became news,” he said.

As a result, stars like Leinart and Reggie Bush became bigger celebrities, and were in demand not just from outlets like Sports Illustrated and USA Today but from People Magazine and Entertainment Weekly. Leinart was especially sought-after because of his associations with Hollywood B-listers like Wilmer Valderrama and Nick Lachey and later when he began dating Paris Hilton.

That led to Leinart acting more like a celebrity than the typical college football star, noted Wolf.

“Leinart became available once a week to the media,” Wolf said. “His first year (as a starter) you could just go up to him. But he became less and less accessible as time wore on. He also became less cooperative and became a worthless person to talk to because he didn’t say anything. I kinda abandoned talking to him because he became really guarded.

“He did that on all levels. He didn’t sign autographs for anybody. He didn’t want to talk to fans. Even a lot of the players felt he didn’t want to talk to them.”

Indeed, his celebrity, and the resulting questions about whether he was too consumed with it and not serious enough about football, was cited as one of the reasons why he dropped to 10^th in the NFL draft after he was projected to go among the top three.

While Leinart was becoming a celebrity at USC, he helped attract other celebrities to the program. Although other programs might attract the occasional famous name — actor Matthew McConaughey often attends Texas games, while country music star Toby Keith is a regular at Oklahoma games — USC has been a magnet for many, including Snoop Dogg, Will Ferrell, Spike Lee, Henry Winkler, George Lucas, Dr. Dre and Kirsten Dunst.

The final word on the often imperceptible line and between sports and entertainment and the absurd lengths to which some in the media go to cover them belongs to Downey, who remembers this classic moment:

“A few years ago at a ‘Monday Night Football’ game in Chicago, ABC’s sideline reporter Lisa Guerrero ‘reported’ that Paris Hilton told her before the game that the media made too much of her supposed relationship with the Bears’ Brian Urlacher and should respect her privacy. Al Michaels responded, on the air, something like, ‘If she doesn’t want publicity, maybe she shouldn’t have come to a Bears game wearing a Brian Urlacher jersey.’”