Catt: Farrell can be perfect 10

Of all the fascinating subplots at the Aviva Stadium on Sunday, few will be as intriguing as the match-up between the two fly-halves, Jonny Sexton and Owen Farrell.

On the line will be potential Grand Slams and personal supremacy — but above all, both will be looking to lay down a marker for the Lions’ No.10 jersey for next summer’s tour to Australia.

It is astonishing how quickly things can change. Heading into England’s game with New Zealand, Farrell was not even his country’s first-choice; but two superb displays, against the All Blacks and Scotland, have changed perceptions of this teak-tough 21-year-old.