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Jay-Z is 'worried' about how much Rihanna is working.
A source told Look that the rapper and head of Rihanna's record label was worried about the singer's schedule.
They said: 'Rihanna's professional, works hard and stays away from drugs and alcohol, but Jay wants her to be careful.
'He told her to take a holiday for a week- she's been working flat out and needs to get over the bronchitis, which he's sure she's developed as a result of stress.
'He told her she'll be alright, but to keep her head down.'
Jay-Z is also worried that the singer could get back in touch with Chris Brown.
The source said: 'Jay said she is a role model for a lot of kids. A little bit of controversy is alright, he said but too much and she cold very easily lose all the respect she has worked so hard to win overnight.'