With Leinster having squeezed home by two-point margins in their past two PRO12 matches, their recent form has been unimpressive.
Eleven days ago they pipped Ulster 22-20 at Ravenhill, where the hosts played with 14 men following loose-head Tom Court's 16th minute dismissal for a tip tackle on Leinster lock Devin Toner. Against a seven-man pack, the defending champions failed to dominate.
On Saturday night they made heavy weather of seeing off Edinburgh at the RDS, a ground where the Scots last won in November 2005. That one finished 15-13 to the Matt O'Connor-coached hosts.
When the question as to whether or not Leinster's recent performances and results meant this might be a good time to be playing them in a PRO12 semi-final, O'Connor's Ulster counterpart Mark Anscombe was guarded in his reply.
"Who knows?" the New Zealander said. "But one thing I can tell you is that they've been there and done it, so experience in these situations counts for a lot.
"Don't underestimate them or think that because we held them with 14 last week, then with 15 on the field we'll go and beat them. It would be silly and foolish to think that way," Anscombe warned.
"They're a quality team. Look who they have in their team; look at the internationals they have there, look at the internationals on the bench. That's quality.
"[If] we underestimate them, we will not get the result we want. What we need to do is what we did on Saturday, back ourselves and believe that we're good enough to do it. If we do that we'll back ourselves to do the job."
Leinster have ended Ulster's season each of the past three years.
In 2011 the southern province were 18-3 winners of the old rivals' Magners League semi-final clash at the RDS. Twelve months later they went head to head again, this time in front of 82,000 at Twickenham where they met in the Heineken Cup final. Leinster won that one 42-14.
Last season they squared up again, in the PRO12 final. That, too, was at the RDS and for the third year running Leinster emerged on the right side of a 24-18 scoreline.
Ulster lock Dan Tuohy – who captained Ulster on Saturday night at Thomond Park – admitted that hat-trick of defeats still grate on him.
"I have plenty of motivation against Leinster, we all do," he said. "They beat us fair and square in the Heineken Cup final – they blew us away.
"Last year we gave ourselves too much of a mountain to climb early doors and just didn't do ourselves justice, to be honest.
"That was the most disappointing thing; we did the double over them last year in the league and when it came to the final we didn't do ourselves justice.
"Now, two more games to go. We're a semi-final, final team. It's just [about] taking the next step. Believing is one thing, but actually going out and doing that is quite another.
"We're desperate to right the wrongs from the last couple of years and prove to ourselves that we're capable winners."