Nag doing Guest Role in P Vasu film , with Vishnu as Hero

Tamil director P Vasu might have given biggest hit to superstar Rajnikant with Chandramukhi but his last two films - Maharadhi with Balakrishna and a Tamil Film with his son as hero (Thottal Poo Malarum) turned out to be biggest duds.

More than the commercial failure, his taking and the story content he has chosen for those films are far from appreciable. One wonders then why did our top star Nagarjuna accept to do a guest role in his next Telugu film starring Vishnu as hero.

It seems he is doing for his good friendship with Mohan Babu but making a film with P Vasu might not be a good option at this time though he was once a 'hit' director. Why not encourage new directors instead?