Rihanna's boyfriend is preparing to propose.

The 'Rude Boy' singer has been dating baseball star Matt Kemp since the beginning of the year and friends say the sportsman is now ready to pop the question because he knows she is 'The One'.

A source close to the couple told Us Weekly magazine: "They are in love. Seeing them interact, it's definitely possible he could propose - but it'd have to be a long engagement, because they're both so focused on their careers."

A close friend of 22-year-old Rihanna - who was assaulted by her ex-boyfriend Chris Brown in February 2009 - claims she is also completely smitten with Matt, 26, because he "centres her".

The pal said: "He centres her, as he has a more normal life. He allows her space, but they text and talk all the time. And they really have fun like kids when they're together. They like to laugh and be silly."

Rihanna has previously admitted spending time with Matt helps her escape the stresses of her hectic lifestyle.

She said: "I have a boyfriend. I'm so happy. I feel really comfortable, and it's so easy. I have such a chaotic life, but at the end of the day, that is just my peace. It keeps me sane talking to him and talking to my family."