After Leinster's bonus-point win over the Dragons last night, Rob Penney's side will have to beat Zebre at Musgrave Park tonight in order to return to the summit.
The likes of Tipperary's Donnacha Ryan & Tommy O'Donnell, as well as Simon Zebo, will all be hoping to make an impression on the Ireland coaching staff ahead of next week's Six Nations trip to England.
Ireland coach Joe Schmidt has admitted that he'll be paying close attention.
Kick-off in Cork is at 6:45.
Conancht host Edinburgh from five o'clock.
And the Cardiff Blues face the Glasgow Warriors at the Arms Park from 6:30.
