The duo went under the knife to fix the knee and back complaints that caused them to miss Ireland’s Six Nations victory over England in Lansdowne Road on Saturday, with Heaslip facing an unknown spell out, while Kearney is likely to be out for at least a month.
But Leinster’s strength in depth was on show in the starting XV Leo Cullen named for today’s Guinness PRO12 clash with Cardiff at the RDS, with Ireland caps Dan Leavy and Josh Van der Flier named in a strong backrow, while Joey Carbery starts once more at full back.
Kearney and Heaslip – who boast 171 Ireland caps between them – would be a huge loss to any club, but Leinster appear better placed than most to deal with their absences.
“It’s definitely a loss, if you think what’s coming up, but that’s the nature of the business we’re in. It’s another chance for the guys to come in,” Cullen said.
“The experience they have will hopefully stand to the group, particularly as you’re into the business end of the season now.
“Jamie’s unbelievable resilient and a great pro, so if anyone could turn around an injury quickly, it’s likely to be him.
“Three or four weeks is the most he’s been out, so it’s a pretty phenomenal run he’s had over the course of his career.
“But he takes really good care of himself, he’s a great example to the young players we have.”
Kearney’s surgery has also been put in the ‘minor’ category, and the Louth man could yet play a part in the semi-final should Leinster make it.
Sean Cronin (hamstring) and Jack Conan (calf) narrowly missed out on selection, along with Zane Kirchner (hamstring), with the trio hopeful of inclusion next weekend.
Johnny Sexton, as expected, sits out today’s game, but Cullen is hopeful the star out-half will be ready for the visit of Wasps.
“He didn’t train, but he was in and around this week getting treated and he’s good to go hopefully for the start of next week,” he said.
“He took a couple of bangs during the game against England, a couple of late hits. Johnny doesn’t shirk it, he’s in the thick of everything and you can see the physical toll it takes; he’s there fighting tooth and nail until the end. It’s great to see him fit and well, getting that run of games from France through to England.”
Luke McGrath and Dan Leavy start today, two more Leinster players who tasted life at Test level against England, while Carbery - who impressed in the No10 shirt earlier this season, stays at No15, with Ross Byrne at out-half.
Skipper Isa Nacewa, who starts on the wing, was full of praise for the 21-year-old who made his Ireland debut last November as a second half replacement for Sexton in the All Blacks win in Chicago.
“Joey’s class, he really is,” Nacewa said. “He works really hard on his game, he works hard in the analysis room, he’s learning as he goes and he takes it all in his stride. It’s very hard to frazzle Joey, he just gets on with it, and that’s probably why he’s so exciting out on the rugby field and so much fun to play with.
"You can see how electric his footwork is, he has great kicking out of hand, he plays what’s in front of him, he’s a genuine threat every time he’s got the ball in his hands. He’s had international experience for the last seven months, in a different environment, so he’s learning along the way.
"He’s learned from Irish camp, he brings those eyes and ears back into Leinster, he’s a threat, he’s always fun to play with.”