Six Nations 2013: England coach Stuart Lancaster rooting for Billy Twelvetrees to light up centre ground England have been searching for so long for a midfield axis that combines physicality with deftness. Lancaster disclosed on Thursday that he did not consider switching Owen Farrell infield to the No 12 shirt that he wore on his debut against Scotland in the opening game of last year's championship. Farrell is now seen purely as a fly-half and England need to hit upon a centre pairing that will last the course. Well as Barritt and Tuilagi played against New Zealand, there is still a feeling that England need a more creative influence at inside centre. Twelvetrees could be the missing link. "I've always wanted to have ball players in my back line as well as players with pace and physical presence," said Lancaster, who has moved Barritt across to the outside centre role. It wasn't just that we scored tries against the All Blacks. Owen managed the game so well, kicked his goals and put us in the right areas of the field. Owen has been exceptional at fly-half for Saracens since then. That's why we're keeping him at No 10 and why Toby [Flood] is going to have to work hard to get the shirt back. A Farrell-Twelvetrees partnership does offer England scope. Twelvetrees has played a lot of rugby at fly-half himself although he has now set himself on being an inside centre. His kicking game is more polished, as well as longer, than Barritt's and he has more nuances to his play. Barritt, of course, has been an absolute rock of dependability for England, powerful, too, and Twelvetrees knows that he has to take command of situations. He certainly does not see himself as a stop-gap solution. "You've got to make the position your own, impose yourself or there's no point being there," said Twelvetrees, who moved from Leicester in the close season, frustrated that he was not a regular starter and with a view to enhancing his international prospects. The move has been good for me. My job is to bring some control to the play and get us to the right areas of the field. This is my time now to try and really nail it down. I've got no excuses. It's up to me. Lancaster admitted that there had been several "tight" selection calls, notably at prop, hooker and scrum-half. Aside from the switch in the centre, there is only one other change, also injury-enforced, from the side that beat New Zealand 38-21 in December with Joe Marler stepping in for Alex Corbisiero. Tom Youngs hangs on to the No 2 shirt ahead of the more experienced Northampton hooker, Dylan Hartley, while brother Ben has held off the persistent challenge of Danny Care at scrum-half. "That's the position, at No 9, that I do most thinking about as both are high-quality players," said Lancaster. Both will get time in the Six Nations. At the moment, you're rewarding the player who has got the shirt. The fact that Tom [Youngs] has managed to hold off someone of Dylan's calibre shows how much trust we have in him. Lancaster revealed that he had had a word with Joe Marler, who has edged the vote at loosehead ahead of Mako Vunipola, about his discipline. The Harlequin prop has picked up two yellow cards recently for getting involved in scuffles. The entire squad was addressed by forwards coach, Graham Rowntree, on Thursday morning on the need for discipline. England still lack experience. Their eight man bench has more caps (230) than their starting XV with 191 caps.