In the short term, Farrell will know that his side will face a ferocious response from the All Blacks in Wellington on Saturday. Not only is the series on the line, but there is also tremendous pressure on his counterpart Ian Foster, and many of the players who will be desperate to play in the World Cup next year.
Foster has come in for a lot of criticism following the defeat on Saturday, the sixth of 23 Tests in charge. The All Blacks have also dropped to fourth in the world rankings, and when the public opinion turns, it usually happens very quickly; as it did to previous head coaches John Hart and John Mitchell following respective semi-final defeats in the 1999 and 2003 World Cups.
I think there has been an impact on New Zealand rugby now that the South African teams are playing their rugby in Europe. New Zealand sides have definitely missed the combative nature of rugby against the South Africans.
But New Zealand rugby traditionally has been brilliant at adapting really quickly and the All Blacks are renowned for their reaction in the face of adversity. Ireland know what is coming.
A series win would ensure Farrell's men go into the World Cup next year as serious contenders. But it will be even more critical for the All Blacks. Another defeat and the clamour for change may be hard to ignore.