Ulster and Leinster have both named entirely changed starting teams from their most recent outings for Saturday's Pro14 dead rubber.
Wing David Busby will make his first Ulster appearance in nearly a year as Darren Cave captains the side.
Johnny McPhillips and Dave Shanahan are named in Ulster's half-back roles.
Ulster-bound Jack McGrath is selected in the Leinster front row as fly-half Ross Byrne captains Leo Cullen's side for the first time.
Ballynahinch player Busby last featured in Ulster's European Champions Cup play-off win over Ospreys last May as he has been out of action since then because of a serious knee injury.
In their last outing, Ulster secured their Pro14 home quarter-final against Connacht by impressively beating Edinburgh 29-7 two weeks ago while Leinster's starting XV is totally altered from last weekend's European Champions Cup semi-final win over Toulouse.
Academy back row Marcus Rea is in line to make his Ulster senior debut after being named on the bench. Rea's brother Matty will start in Ulster's back row.
Tommy O'Hagan and Jack Owens will make only their second Ulster appearances if they come on as replacements.
Skipper Cave will be partnered by Peter Nelson at centre while the Ulster pack includes Andy Warwick, John Andrew and Ross Kane plus Ian Nagle, who is on a season-long loan from Leinster.
Such is the strength in Leinster's squad, their line-up includes Ireland internationals Fergus McFadden, Noel Reid, Dave Kearney.
Skipper Byrne is partnered at half-back by Nick McCarthy while the back row includes emerging talents Max Deegan and Caelan Doris.
Ireland Under-20 player Ryan Baird is in line for his Leinster debut after being included in the replacements.
Busby comeback 'ahead of schedule'
Ulster coach Dan McFarland said Busby's return comes ahead of schedule in the contest between the sides who contested a thrilling European Champions Cup quarter-final won narrowly by Leinster four weeks ago.
"Dave's planned comeback date was not even now and he has worked so hard to come back," added the Ulster coach.
"He has played for Ballynahinch and I watched that game and he had a fantastic game for them and it will be really special for him to be able to play against Leinster at Kingspan Stadium.
"For guys like Marcus Rea this is going to be the biggest day of his rugby career. Marcus was not playing in the [Champions Cup] quarter-final so this will be his day and everyone has to respect that."
Ulster: Lowry; Busby, Cave (capt), Nelson, Kernohan; McPhillips, Shanahan; Warwick, Andrew, Kane, Nagle, O'Connor, Matty Rea, Ross, Reidy.
Replacements: McBurney, O'Hagan, O'Toole, Timoney, Marcus Rea, Stewart, Owens, Lyttle.
Leinster: O'Brien; McFadden, Tomane, Reid, D Kearney; Byrne, McCarthy; McGrath, B Byrne, Bent, Murphy, Dowling, Deegan, Connors, Doris.
Replacements: Kelleher, Dooley, Abdaladze, Baird, Penny, Patterson, Frawley, Daly.