In the 2011 world cup success, though, the main hero was Yuvraj singh but Zaheer khan played a very crucial role in giving team India early break throughs almost in the every match of the tournament. After Zaheer there is no fast bowler for India, from last two/three year we have seen many bowlers come and go out of the team except for Bhuvaneshwar kumar. Bhuvneshwar has capability to swing the ball both sides and has a decent pace and he is gaining maturity in bowling.
Now the point is that can he give the early break throughs as often as given by Zaheer khan in WC 2011. By the time of 2011, Zaheer was far matured bowler than Bhuvneshwar as of now for WC2015 and next option for Team India is Ishant sharma who is far more experienced than Bhuvaneshwar kumar but Ishant is very inconsistent and reliability on him has been proved very costly some times but if he controls his bowling with right temperment then his bowling could be helpful to defend the title.
In order to defend the WC, though, we do not have extraordinary bowlers who deliver great spells in the alian conditions like Australia and New zealand; the existing bowlers should have belief in their abilities and should try to give early break throughs and should try to keep tight in the death overs this is the key to succeed. May new stars emerge in bowling for Team India.