Manu Tuilagi. Is he the answer or the problem?

It is a question worth asking because the Leicester centre is close to fitness and might even be available during the Six Nations. Whether the head coach Stuart Lancaster plays Tuilagi is another matter, but in the not too distant future the England coach will have to decide what role the Samoan force of nature has in his World Cup plans.

Does he return to the midfield colossus who was at the heart of England's biggest win in the Lancaster era – the autumn Test against New Zealand 15 months ago – or does he stick with the current combination which, through luck, judgment, accident or design, is fast becoming quite a force.

On Wednesday Lancaster was suggesting that the first Test against in New Zealand on 7 June would be a big day in his World Cup reckoning, but in the spreadsheet which the England coach admits is in his mind, he has already started mapping out the alternatives.

If he sticks what does he get? In the past two games the fly-half Owen Farrell has certainly played flatter – not an end in itself, but important when challenging defences to make decisions under pressure. Why? Well he's helped by having wings like Jack Nowell and Jonny May running off his shoulder and occupying defensive minds, but the key seems to be Luther Burrell, playing out of position at outside-centre when Northampton see him as a 12, and the running lines he has taken in both Paris and Edinburgh.

With Billy Twelvetrees improving after a poor autumn, Lancaster also has the creative inside-centre he says he wants and the collective effect seems to have sowed seeds of doubt in both French and Scottish midfields.

It is almost a law of physics that when an attack takes the ball up to an onrushing defence it is the defenders who blink first in the game of chicken. Collectively they "sit" to assess the oncoming threat and that's what has been putting England on the front foot and giving Farrell the chance to mix his game; a dummy and timed pass which created Burrell's first Test try in France, the dummy and dart which got Burrell to within a yard at Murrayfield.

Against that there is the threat of Tuilagi, a powerhouse who likes to run all over the opposition. Like a forward, he likes to get his hands on the ball early and get up a head of steam. It's a real threat when it works and takes two or three to bring Tuilagi down, but more predictable because it gives a defence time to settle, something they don't have with runners like Burrell, Mike Brown, May, Nowell and especially Billy Vunipola around.

Currently England have plenty of options behind a winning pack, but if Lancaster feels he can't do without Tuilagi then were does he go? Drop an increasingly confident Twelvetrees just when England are feeling the benefit of an all-court game and put Tuilagi at 12 and a centre axis with Burrell is unlikely to increase creativity. In fact almost every attacking move would have to come off Farrell, one of the problems of the past two seasons.

So put Tuilagi on the wing? It's an option seen by some, but wing is a specialist position and does Tuilagi have either the pace, or the experience of living under the kind of aerial bombardment Jonny Sexton inflicted on Wales last weekend. Luckily, it's not an urgent problem for Lancaster, whereas another midfield issue could become one overnight.

If Farrell tweaks a hamstring or goes down with the flu next Thursday or Friday does Lancaster phone Toby Flood and recall the Leicester man to the colours? If not he's pretty short of experienced fly-half options. He has one with no Test experience, George Ford, and another, Freddie Burns, who has three caps, but is pretty low on form.

Ford is currently the deputy of choice, but so far in this Six Nations he has failed even to make the replacements' bench – the make-up of which is almost another column in itself – and it is hard to see Lancaster willingly changing his matchday 23 for Ireland. At this stage in his Test career the chance of a championship is compelling for both coach and team and a win at Twickenham in eight days would probably mean Lancaster also standing pat against Wales.

With 18 games left until England begin their quest for a World Cup on home territory, 7 June at Eden Park, Auckland, against the reigning champions is fast acquiring special status – something which is not helped by the Premiership grand final half a world away and seven days earlier and a Barbarians game at which England will be probably be expected to field something like a third XV.