England cricketer Jos Buttler has reached a stage where 'potential' alone cannot be the criteria on which he will continue to merit Test selection. Admitting that he has made too many mistakes, Buttler now wants to repay the faith England have continued to show in him by selecting him for the Sri Lanka series despite him having an ordinary outing in South Africa Tests. <p></p> <p></p>In five matches against New Zealand and South Africa combined, Buttler has managed a top score of 45. <p></p> <p></p>"I've got massive self-belief in myself, and a lot of it is about fulfilling potential," he was quoted as saying by <em>ESPNcricinfo</em>. "I'm too old now to get picked on potential but I feel that I haven't got to the level I know I can get to, and that's a big driver for me. That's my aim every time I turn up to practice, to try and get better and try and reach that level I am capable of. I've always maintained that belief." <p></p> <p></p>The 29-year-old Buttler has so far played 41 Tests since making debut in 2014, scoring 2127 runs at 31.74. <p></p> <p></p>Despite the success he has tasted with England's limited-overs side, especially his role in their maiden ODI world cup win last year, Buttler continues to term Test cricket as the 'most rewarding' format. <p></p> <p></p>"I'm very committed to Test cricket," Buttler said. "It's the best form of the game, it's the hardest form of the game. That's what makes it - when you have good moments - the most rewarding. You want to be a part of that." <p></p> <p></p>"My performances may have meant that decision would be taken out of my hands. But fortunately for me I'm on the tour [to Sri Lanka] and really excited about it. I enjoyed the last tour there that we won back in November 2018. I've got good memories from that tour and looking forward to going back." <p></p> <p></p>Buttler doesn't want to blame his indifferent form in Test cricket to punishing schedule giving the examples of his contemporaries who are managing to excel across formats despite that. <p></p> <p></p>"There's a crop of guys who are the best in the world, and they're the best across all formats. They manage to do it," Buttler said. "You need to find breaks in your schedule - your mind is your biggest asset so you need to have time to get that to the best place when you turn up. That's a big skill. But the best players can play all formats. You want to play all the games, be involved in all the formats. I certainly do." <p></p> <p></p>England will be in Sri Lanka for a two-match Test series starting March 19 and for Buttler it's an opportunity to get back to his best. "Some people are naturally suited to one (format) or the other, but I think you can do it." You've always got to be positive. Obviously I haven't played as well as I'd have liked in the majority of the winter, but you don't become a bad player overnight so I'm looking to repay some faith and get back to playing my best cricket," he said. <p></p> <p></p>He continued, "I just haven't played quite well enough at times. I have made too many mistakes really. When you're playing well you feel like you make the right decisions a lot of the time. You feel in a very good head space. I just feel like I haven't been able do that often enough."