10 Dec, 12:23
Ireland's John Lacey will referee his first ever RBS 6 Nations match in February, while Alain Rolland is also included in the Elite Panel in what is his last season.
The Ospreys, now confirmed as second seeds, will host the third-placed side at Swansea's Liberty Stadium on Friday, May 11 (kick-off 7.35pm).
Currently Munster and Glasgow Warriors sit third and fourth respectively, but Ulster and the Scarlets are still mathematically in the mix for the top four - albeit with favours to depend on from other teams.
Commenting on the push for the play-offs, RaboDirect PRO12 Chairman Andy Irvine today said: "We are now at the business end of the season and are now looking forward to 'Super Saturday' on May 5 to see who makes the top four.
"It promises to be another exciting night of rugby as six out of the twelve teams are in contention for the play-offs."