When Rihanna performed at the NBA All-Star Game last month, it was apparent her stellar vocals were a bit on the weak side, as the singer was reportedly suffering from a bout with bronchitis. The 'Loud' creator hasn't really taken any down time to deal with her health problems by easing up on her appearances, which has caused longtime mentor and friend Jay-Z to take notice.

According to Look Magazine, the Roc Nation head honcho is worried that the 23-year-old is being overworked and that her current schedule is causing her health to deteriorate. "Rihanna's professional, works hard and stays away from drugs and alcohol, but Jay wants her to be careful," a source told the publication.

During the Grammy Awards in February, the 'S&M' songstress fell ill to bronchitis and laryngitis, yet still managed to perform despite the setback such sicknesses could cause her in the longrun. To help Rihanna get her vocals back in tip-top shape, the 'Empire State of Mind' rapper suggests she takes a much needed break.

"[Jay-Z] 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," the source continued. "He told her she'll be alright, but to keep her head down."

The magazine also reports that the veteran rhymer is concerned the red-haired singer could resume contact with former flame Chris Brown, now that a judge recently reduced a restraining order against him. Brown's order is now a Level One, granting him the right to have contact with Rihanna so long as he does not "harass, annoy or molest her."

Watch Rihanna's 'S&M'
if(typeof AOLVP_cfg==='undefined')AOLVP_cfg=[];AOLVP_cfg.push({id:'AOLVP_772550002001','codever':0.1,'autoload':false,'autoplay':false,'displaymnads':true,'playerid':'89761511001','videoid':'772550002001','width':476,'height':357,'playertype':'inline','stillurl':'dynamic','videolink':'#','videotitle':'dynamic','videodesc':''});