Ex-India all-rounder Irfan Pathan has said India's Ravichandran Ashwin will definitely trouble Australia opener David Warner in the upcoming four-Test series. "Because if you look at his history as well, nearly 50% of Ashwin's wickets have come against left-handed batters," explained Irfan. Notably, Ashwin has picked up 89 wickets in the 18 Tests he has played against Australia so far.