Kolkata, Oct 18: Going forward, chinaman bowler Kuldeep Yadav will become India's primary spin weapon, feels veteran bowler-turned-cricket commentator Harbhajan Singh."Kuldeep has shown glimpses of what he can do on a first-day wicket. He is slower in the air and gets the ball to turn both ways. Going forward, he should be India's key and deciding factor. He will be the No.1 spinner in future," Harbhajan said in an interview.Kuldeep was the second-highest wicket-taker against the West Indies in the just-concluded two-match series, picking up 10 wickets. Earlier, Kuldeep played just the second Test in England and was wicketless, bowling nine overs and leaking 44 runs. India lost by an innings and 159 runs.Harbhajan, a lethal and celebrated off-spinner in his time who was part of India's World Cup-winning team, did not want to read too much into that performance."In England, the conditions were seaming and the day he bowled, it was the coldest day in summer. So, for a wrist spinner, it is very difficult. He could not do the things he wanted. He has time and again proved his credentials and the team depends a lot on him and will in the future," said Harbhajan, who was commentating during the England tour and watched Kuldeep from close quarters.Asked about the two-Test series sweep against the West Indies, Harbhajan said the visitors were no side to beat at the moment, adding that this Indian team has in it to win the upcoming Test series Down Under. With Steve Smith and David Warner unavailable, this is their best chance."The result shows that this was a one-sided affair. More than how well India played, the West Indies was not even competing," said Harbhajan, who has 417 Test wickets in 103 matches."They have always produced some match winners, but at the moment I doubt whether they have any. This is worrying for cricket. Sri Lanka is going down, so is Zimbabwe. All these teams used to be so good," said the most successful off-spinner the country has produced.India will play four tests starting December 6 in Adelaide."If we bat well there, we have got the bowling to get them out. Without Smith and Warner, this is our best chance to win a series there," Harbhajan opined.Lauding 18-year-old sensation Prithvi Shaw, who ended the series as the highest run-getter and was adjudged the Man of the Series, and young wicketkeeper Rishabh Pant, Harbhajan said while the former has played fearless cricket, the latter is ready to take over in all three formats."He plays a fearless brand of cricket which is great to see. His confidence is beyond his years and that is due to the number of runs he made in school cricket and Ranji Trophy. This is where credit should go to our infrastructure and the BCCI."As far as Pant is concerned, the way he played in the IPL, he took the game away from the opposition. He has got power, balance and everything what you need as a batsman in the modern era to score runs. He deals in fours and sixes with so much ease."He is someone who is ready to play in all formats. MS (Dhoni) is playing which is great as he will learn a lot from him."