Zac Efron's 'Hairspray' director wants to be his sober coach.

Choreographer Adam Shankman reportedly wants to help his friend - who endured two stints in rehab last year for cocaine and alcohol abuse - following recent concerns about his behavour and is encouraging him to follow the same treatment programme he checked into late last year.

A source told RadarOnline.com: ''Adam sees that Zac isn't on a great path and has even gotten a little sloppy lately.

''And since they've been friends for years, Adam has reached out to Zac and is trying to get him into the same program he completed at Passages in Malibu. He's even offered to be Zac's sober coach.

''Adam really believes in Passages and just wants to see Zac get back into good health.

Adam is said to be keen to intervene before the 26-year-old star's apparent problems affect his career.

The source added: ''Zac has so much to offer and Adam would hate to see him throw away his career.

''If anyone knows what's going on with Zac, it's Adam. And he wants to help.''

Friends are said to be concerned the '17 Again' actor - who celebrated six months sober in December - has fallen off the wagon.

Last month, Zac - who broke his jaw after falling over at home in November - was hit in the face during an altercation in a notorious area of Los Angeles, which he told police had taken place when he had run out of gas on his way to a restaurant.

He claimed as he and a bodyguard were sitting in their car and waiting for a tow truck, he threw a bottle out of the window and it smashed on the pavement near the alleged attackers. He said three men confronted them because they believed the bottle had been deliberately thrown at them. Two men attacked the bodyguard, then Zac got hit on the mouth when he tried to help.

However, sources say Zac's friend - who has requested to remain anonymous - isn't a bodyguard at all, but a convicted drug dealer who has been hanging around the star a lot recently.