Best joins 200 club but Ireland form the goal for him and Kearney
Sexton and Henshaw among the high-profile absentees but there is plenty for Ireland coaches to digest as conference rivals prepare to go head-to-head in Belfast
The Sky cameras are in Belfast but, once again, a Guinness PRO14 clash between two Irish provinces is undermined by the names absent from one of the team-sheets.
Leinster will still fancy their chances of winning at Kingspan Stadium but they've left plenty of stardust in Dublin as Johnny Sexton and Robbie Henshaw are among those given the weekend off before they go into Ireland camp.
Injured scrum-half John Cooney is out for Ulster, as are his normal back-ups Paul Marshall and Dave Shanahan, meaning converted winger Aaron Cairns makes his debut.
He's surrounded by senior players, none more so than Ireland captain Rory Best who will play for his province for the 200th time this evening.
The milestone is important, but proving his fitness to international coach Joe Schmidt is probably the priority for the hooker who made his first appearance of the season off the bench against La Rochelle last weekend.
Rob Kearney, Sean O'Brien and Dan Leavy are in similar boats and all will want to leave a lasting impression on Schmidt.
Level on points in Conference B, this is a crucial fixture for both teams in the race for the play-offs - even if it's at an early stage.
While Best is honoured to have reached such a significant point in his career, unsurprisingly the experienced Armagh man is focused on the challenge at hand.
"It is special," he said. "It really doesn't seem that long ago since the first cap. It would be nice to have that milestone.
"To play 200 times for this province, you'd never dream of that. You dream of playing for them maybe, but 200 caps is, whenever you get away from it and reflect, you'll be proud.
"I think for me personally, it's preparing well to fit into a team that's going well and to do my part."
That challenge is one that Ulster have managed at home in recent seasons, even if they have struggled with Leinster regularly at the RDS.
The Blues haven't won in Belfast since 2014 but despite the absence of Sexton and Henshaw, the pack they have picked looks well capable of securing a result if the home side don't up their game.
"You have to be up for it," Best said.
"We always talk about these interpros and how big they are, especially at the minute, and there's none bigger than Leinster because they are the top province over the last six or seven years now with the way their run has been.
"It's going to be a big challenge for us but it gets you going. We've been reasonably well looked after in the early part of the week and a lot will be about the mental side of the game and making sure that we hit the ground running."
The all-Irish Leinster tight-five will look to gain a dominant foot-hold in the game, with James Ryan partnering Devin Toner in the second-row, behind a formidable front-row of Jack McGrath, James Tracy and Tadhg Furlong.
Up against the locks is Iain Henderson who is the favourite to partner Toner next month and he captains the side from the engine room despite Best's return to the team.
That's just one of the intriguing Ireland match-ups, with Jacob Stockdale's battle with Adam Byrne another one to watch.
But the game is likely to be won in the tight exchanges, with the fliers out wide needing good ball.
It is in this area that the visiting side seem to hold the aces.
Best is aware of what Leo Cullen's men have to offer and knows a victory today would be timely given his side's middling season to date.
"They obviously have some very, very good players," Best said.
"You look across the board and whenever the Irish squad announcement is but there will be a lot of Leinster players in it, which suggests they have a lot of very talented individuals, and a lot of individuals that have come through the Leinster systems, so they know how special it is to play for their province, which they play on.
"I would say it's a special thing about Irish rugby, the provincial set-up, because it means so much more to play for your province.
"Leinster have obviously a conveyor belt of players coming through there and I think that they have some fairly good half-backs and they have a very good back-row no matter which three they pick.
"So I think if you can get that sort of core it makes you a very good team, as you see with them."
Confidence shouldn't be an issue for Leinster who are coming in having secured 10 points in their two Champions Cup games to date, while Ulster are coming off the back of a heavy loss in France last weekend.
"La Rochelle was tough and they will be annoyed coming home," Leinster scrum coach John Fogarty said.
"They were dealing with a juggernaut pack. It was a tough ask. We came undone last year going over to Montpellier to take on a big pack.
"They have been excellent in their opening six games. They have had good results. Technically, you can see they are sharp in what they're doing.
"Their drills are really, really good. Scrum, lineout and maul, they are really tight and really good.
"Jono (Gibbes) brings that level of excellence to what he does.
"They will be really, really up for it, regardless of the results we've had or they've had. A lot of that goes out the window when you play a game against the neighbouring province.
"It is going to be very difficult. Technically, they are very, very good at what they do.
"We need to be mentally right before we go up there. That is something we'll pick up later in the week.
"We're fixing bits now. Later in the week, we need to make sure we arrive ready for a battle.
"We haven't won in Ulster for the last five outings, it's a very difficult place to go, so right now everyone's focusing on getting into the right frame of mind to go up to Ulster, because I think we missed out last year, we went up there not prepared mentally and we didn't come out with anything."
That's the risk for Leinster, but their pack will fancy the chance to put pressure on the inexperienced Cairns and deny him easy ball.
If they can make his night difficult, it'll be half the battle.
Schmidt will be hoping all of his squad members show form while avoiding injury.
His old team look well placed to end their recent run at Ravenhill if they can get things right up front and provide Jamison Gibson-Park and Ross Byrne with a good platform to play off.
ULSTER - C Piutau; T Bowe, L Marshall, S McCloskey, J Stockdale; C Leali'ifano, A Cairns; C Black, R Best, R Ah You, A O'Connor, I Henderson (capt); S Reidy, C Henry, J Deysel. Reps: R Herring, A Warwick, R Kane, K Treadwell, R Diack, J Stewart, P Nelson, L Ludik.
LEINSTER - R Kearney; A Byrne, R O'Loughlin, N Reid, D Kearney; R Byrne, J Gibson-Park; J McGrath, J Tracy, T Furlong; D Toner, J Ryan; D Leavy, J Murphy, S O'Brien (capt). Reps: R Strauss, C Healy, A Porter, R Molony, J Conan, L McGrath, C Marsh, J Larmour.
REF - J Lacey (IRFU)
- Ulster v Leinster, 6.30, Live, Sky Sports/BBC NI
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