Selena Gomez is "worried sick" about Justin Bieber.

The 21-year-old pop star's ex-boyfriend was arrested in Miami Thursday for driving under the influence after cops caught him drag racing on city streets.

And apparently Selena called Justin's mother Pattie Mallette immediately after she heard the news to offer her assistance.

"She has not spoken to Justin yet but has been in touch with his mom, who is also worried sick about her son," a source told

"They are all hoping this is a wake-up call. Selena is just beyond thankful that no one was hurt."

Selena is supposedly concerned that Justin has chosen to surround himself with bad people lately.

According to an insider, she would like to see his former road manager Ryan Good come and give her ex-lover a pep talk.

"Selena is hoping that Ryan will reach out to Justin," the source revealed.

"He's always been a positive influence on Justin and if anyone could talk some sense into Justin, it would be Ryan."

Speculation Selena and Justin have reignited their romance began circulating earlier this month after the former couple posted pictures of themselves hanging out together online.

However a rep for Selena has denied rumours of romance and said the two are just friends.

Justin was officially charged for DUI, resisting arrest without violence and driving on an expired licence in a Miami court on Thursday. He was subsequently released from jail on a $2,500 bond.