Cape Town - With the Rugby Championship looming, Springbok captain Jean de Villiers has warned his team-mates that nobody's spot in the team is safe.Following the Bulls' heartbreaking Super Rugby exit at the weekend, South African rugby fans will now shift their attentions to the Rugby Championship, which starts for the Boks with a Test against Argentina in Soweto on August 17.And De Villiers insisted no player can afford to rest on his laurels as the Boks aim to improve on their third spot finish from last year.“I never feel that I am a certainty for the Boks,” De Villiers told the MyPlayers website in an exclusive interview. “No one deserves to be selected purely on reputation. It’s a great honour and privilege to play for South Africa and something you need to work incredibly hard for.“The moment you start thinking it’s your right you are on the wrong track. There is a lot of competition for places and my place is no different. I have to keep on playing really well, but that being said, I do believe I am good enough to play for the Boks when I’m at my best.”De Villiers also he doesn't mid slotting in at either inside or outside centre for the competition.“I think I have reached a stage where I don’t really care whether I am playing at inside or outside centre and I can honestly say I enjoy both at this stage."