Earls is currently ruled out with a knee injury but until he has heard otherwise, Foley is determined to give him every chance to prove his fitness for the four European games in October and December.
However, among those sidelined until Christmas at the earliest are second-row Donnacha Ryan and hooker Mike Sherry.
On the credit side, Damien Varley is in the group having recovered from a nagging foot injury and another hooker included is Eusebio Gwinazu, who has signed a short-term contract until the end of December to atone for the absence of Sherry and Niall Scannell.
Australian centre Andrew Smith figures in his first European Cup squad and there are also places for Academy graduates Shane Buckley and Johnny Holland, both promoted to development contracts at the beginning of the season.
Robin Copeland, the former Cardiff Blues number eight, is also there and set to replace the departed James Coughlan as the first choice number eight.
Two additional players may registered during the pool stages, each to replace a player previously registered.
Denis Hurley, Felix Jones, Simon Zebo, Keith Earls, Ronan O’Mahony, Gerhard van den Heever, Andrew Smith, Johne Murphy, Ivan Dineen, Andrew Conway, Ian Keatley, JJ Hanrahan, Johnny Holland, Conor Murray, Cathal Sheridan, Duncan Williams.
Stephen Archer, BJ Botha, Alan Cotter, James Cronin, Dave Kilcoyne, John Ryan, Eusebio Guinazu, Duncan Casey, Damien Varley, Kevin O’Byrne, Dave Foley, Billy Holland, Shane Buckley, Dave O’Callaghan, Donncha O’Callaghan, Paul O’Connell, Paddy Butler, Sean Dougall, Tommy O’Donnell, Peter O’Mahony, CJ Stander, Robin Copeland.