Celtic League/Ospreys v Leinster:This is the business end of the season and for all the complaints about them, at least Leinster, to their credit, are still in negotiations for silverware. Though there will still be a fortnight of the campaign to run, tonight's daunting assignment in front of a hostile 10,000-plus crowd may well close the deal one way or another.
The Ospreys' gritty 19-6 win against Llanelli last Tuesday may have left them looking a little wearier than Leinster, but it also pushed them to within five points of Michael Cheika's league leaders with a game in hand.
This is their final home game of the season and they are unbeaten in all 15 competitive games at the Liberty Stadium this season; indeed their sole defeat in their last 26 matches there was courtesy of David Humphreys's last-ditch, league-clinching drop goal via a crossbar in May.
Nor have Leinster been helped by the loss of the league's all-time leading try scorer, Denis Hickie, with a lower-back strain. He joins Brian O'Driscoll on the sidelines, which seriously reduces Leinster's firepower and denies them two of their leaders for what is likely to be a severe mental test.
Luke Fitzgerald returns to the side, the only other change from the team that eked out victory against the Dragons last time out seeing the return of Chris Whitaker to the starting line-up in place of Guy Easterby.
The Ospreys will have fitness tests on their man of the moment, James Hook, who scored all their points on Tuesday and has been named on the bench, though Cheika for one won't be surprised to see Hook start.
Lyn Jones has made four changes in his tight five, including his entire frontrow, and the anticipated loss of the abrasive Brent Cockbain is offset by the return of Alun Wyn Jones.
Cheika concedes Leinster will have to up their game from that win over the Dragons, only their second of the league away from home and one of only three wins on the road this season.
The flip-side of that coin, as Cheika points out, is that Leinster are still top of the table and are unbeaten at home in all competitions since November 2005, and in this Leinster are not unique. Most teams struggle to achieve away wins, not least in a league where the crowd is liable to influence "home" touch judges and compound some poor officiating.
Not the least significant aspect of Leinster's win in Rodney Parade was the strong performance of Malcolm Changleng, though it's noteworthy the experienced Nigel Owens runs one touchline tonight.
In conceding only six penalties in that game, despite decidedly tetchy exchanges and much provocation, Leinster showed a discipline they will need to repeat tonight, while hoping the Scottish referee, Peter Allen, will be as strong as Changleng was.
Defensively, too, the rush defence used by the Ospreys, à la Wasps and most of the Welsh sides, generally discommodes Leinster's running game.
"That's possibly true but each team who employ a blitz have their own nuances and whereas Wasps would employ more of a hook, the Ospreys really fill the field and come up straight all the way to the openside winger," said Cheika.
"Sometimes you can face a line of seven defenders. So it will be a big test of us strategically and we've been working hard on coming up with a few plans.
"We won't make many holes or make as many one-off breaks as we might normally do so we'll have to be patient."
Cheika adds - without giving much away - they have been trying to modify their style.
Leinster have struggled for quick ball in recent league games, and to "get onto the front foot more and produce quicker ball, a lot of that comes down to making good plays", says Cheika.
In the experienced Whitaker-Felipe Contepomi axis, Leinster do have good decision-makers and, despite the absence of Hickie and O'Driscoll, aren't lacking in gamebreakers either.
But the Ospreys are on fire, and though weary coming off a five-match winning run in the league and a hat-trick of home wins over the other Irish provinces, their confidence must be sky-high.
The statistical evidence suggests that were Leinster to succeed where Australia, Stade Français, Sale and all their Celtic rivals have failed, it would rank as arguably their best victory of the season.
OSPREYS: S Terblanche; N Walker, S Parker, A Bishop, S Williams; S Connor, J Marshall; P James (capt), H Bennett, A Jones; J Thomas, A W Jones; R Jones, R Pugh, F Tiatia. Replacements: R Hibbard, D Jones, M Powell, L Beach, M Roberts, J Hook/ AN Other, L Byrne.
LEINSTER: G Dempsey; R Kearney, S Horgan, G D'Arcy, L Fitzgerald; F Contepomi (capt), C Whitaker; R Corrigan, B Blaney, W Green; T Hogan, M O'Kelly; S Keogh, K Gleeson, J Heaslip. Replacements: S Wright/C Healy, B Jackman, O Finegan, C Jowitt, G Easterby/P O'Donohoe, C Warner, K Lewis.
Referee: Peter Allan (SRU).
Previous meetings: (03-04) Ospreys 25 Leinster 36; Leinster 16 Ospreys 16; (04-05) Ospreys 11 Leinster 3; Leinster 12 Ospreys 15; (05-06) Ospreys 22 Leinster 20; Leinster 38 Ospreys 21; (06-07) Leinster 45 Ospreys 22.
Formguide: Ospreys - W W W W W. Leinster - W W W L W.
Forecast: Ospreys to win.
