New Delhi, Nov 29 : Former South Africa cricketer AB de Villiers raises concern over Royal Challengers Bangalore (RCB) bowling attack as RCB released their mainstay bowlers like Harshal Patel, Josh Hazelwood, Wanindu Hasaranga. ahead of the Indian Premier League season 2024 auction. AB de Villiers showed concern over RCB's bowling line up and said that RCB need to add more firepower to their bowling attack and that RCB has let go off many of their match-winning bowlers. "It is the area where I would be worried. Obviously, there is Mohammed Siraj there, Reece Topley, and some experience there, but if you see the released players list, they let go of Wanindu Hasaranga, Harshal Patel, and Josh Hazlewood. Those three have won them a lot of games in the last couple of seasons, especially Hazlewood; he had just this way of controlling that bowling lineup," said de Villiers. RCB are left with Mohammed Siraj and Reece Topley are left among the bowlers with international experience, and with Rs 23.25 crore in their kitty RCB will look for an overhaul change in the bowling attack. However, De Villiers acknowledges the concerns over bowling performance of RCB in last few year and how it affected the. He remains hopeful of RCB grabbing some big names in the auction to bolster their bowling attack, scheduled to held on December 19. "It has been a well-known fact that RCB's bowling has been an area of weakness over the years. Yes, the batters also made a mess at times, but you need to play as a team. You need to gel together and understand each other. More often than not, there has been this feeling of making silly mistakes, not getting the discipline right, and not doing the basics well under pressure. We know how difficult it is to bowl at the Chinnaswamy Stadium," said de Villiers. RCB traded Cameron Green into their side from Mumbai Indians for Rs 17.5 crore, which has made a significant impact on their auction purse. RCB have a total of 6 slots to fill out of which 3 are overseas slots. AB de Villers announced his retirement from IPL in 2021 after being associated with the RCB franchise since 2011. De Villiers scored 5162 IPL runs with a staggering strike rate of 151.69. Earlier this year, de Villiers was inducted in RCB's hall of fame for his crucial contribution in the team. /IANS