Keatley has to outplay Farrell for Munster to win
Munster v Saracens
Thomond Park, Tonight 7.45 (Live BTS 2)
Coach Anthony Foley allows an eye into where this titanic tussle will be won and lost by bringing two new faces into the front row in BJ Botha and James Cronin.
Ireland squad members Stephen Archer and Dave Kilcoyne are demoted to bench duty in what is probably a rotation policy.
There is still no place for Wexford's Robin Copeland as Foley shows loyalty to his back row, particularly Tommy O'Donnell for his yellow card against Sale.
The slow reactions of the big, immobile centre partnership between Andrew Smith and Denis Hurley to what Sale were doing in round one must be a cause for concern.
The half-backs Conor Murray and Ian Keatley will be central to how Munster try to manipulate the Saracens back three with wings Dave Strettle and Chris Ashton on fire.
Sarries have been able to recall England out-half Owen Farrell into what is a particularly strong defensive unit.
There is no doubt Foley would have sent his big runners, like CJ Stander straight down that channel were Charlie Hodgson there. Farrell is a different physical prospect.
There could be opportunity to exploit the Saracens lineout as their captain and leader Alistair Hargreaves is ruled out with injury.
Paul O'Connell will relish the challenge to find a weakness there and to strengthen that area from what was an imperfect return against Sale last Saturday.
The selection of Jim Hamilton for Hargreaves brings a different dimension in that the Scotland second row is a bigger, stronger man, more suited to the maul and scrum.
It all looks set for one almighty dust-up.
Munster: F Jones; A Conway, A Smith, D Hurley, S Zebo; I Keatley, C Murray; J Cronin, D Casey, BJ Botha, D Foley, P O'Connell, P O'Mahony (capt), T O'Donnell, CJ Stander.
Saracens: A Goode; C Ashton, M Bosch, B Barritt (capt), C Ashton; O Farrell, N de Kock; R Barrington, J George, P du Plessis, G Kruis, J Hamilton, K Brown, W Fraser, B Vunipola.