India's skipper Virat Kohli with MS Dhoni and other team mates during the first ODI match against Sri Lanka at Rangiri Dambulla International Cricket Stadium in Dambulla, Sri Lanka, on Sunday. Pic/PTI

Variation in any bowling attack makes it lethal and that's precisely the reason why bowling coach Bharath Arun is in search of a potent left-arm speedster, who enables Indian team to have all bases covered.