Former Maori All Blacks fly-half Ihaia West said La Rochelle face a "big balancing act" after reaching their first Champions Cup final thanks to Sunday's 32-23 home victory over Leinster.
West's men will play three league fixtures in seven days due to Covid-19 postponements before meeting fellow Top 14 outfit Toulouse in the decider at Twickenham on May 22.
The fixture will be played in front up to 10,000 spectators in London after an easing of coronavirus restrictions and will be a sixth final between two Top 14 outfits.
"It's going to be a big balancing act. It's going to be a big emphasis on the whole squad," the 29-year-old said.
"The depth in the squad will be really tested. If we do our homework it should hold us in good stead."
West claimed 22 points as France back-rower Gregory Alldritt and Australia lock Will Skelton scored tries at Stade Marcel-Deflandre.
"They hung in there well, keeping the scoreboard ticking 3,6,9," Leinster head coach Leo Cullen said.
"A credit to West, he was very accurate with his kicking, which kept them in the game and then pulled them out of reach in the second half. It's incredibly frustrating, the guys are gutted," he added.
West and ex-New Zealand scrum-half Tawera Kerr-Barlow overcame injuries to start for Jono Gibbes's hosts.
Cullen, who won three European titles as a player, handed Ross Byrne his 100th appearance with captain Johnny Sexton sidelined with concussion.
The Irish side dominated the opening 10 minutes and were rewarded as Tadhg Furlong burrowed over after the hosts' flanker Wiaan Liebenberg was shown a yellow card.
West and counterpart Byrne exchanged shots at goal, which included a drop goal for the Kiwi, as the visitors led 13-12 at the break but the French side finished the half on top.
The pair then added a penalty each to make it 16-15 after 15 minutes of the second half.
- La Rochelle pressure -
La Rochelle then re-took the lead and control of the tie with 23 minutes to go.
West was succesful with a three-pointer after Ireland winger James Lowe was sin binned for an infringement at a ruck near his own line.
The former New Zealand under-20s playmaker failed at the posts for the first time with 20 minutes to play.
La Rochelle camped inside the Irish 22m before finally breaching the away defence thanks to Alldritt with 13 minutes to go.
Alldritt picked from a ruck to dive over and a dozen home fans, watching on from an apartment block overlooking the pitch, flew their flags in celebration.
West's conversion took the score to 25-16 before Skelton made sure of a maiden appearance in the final for La Rochelle, promoted from the French second-tier in 2014, within the closing five minutes crossing from a driving maul.
Byrne claimed a consolation try for Leinster, who will have to settle for just a Pro 14 title this season which was won in March.
The hosts celebrated the victory with dozens of fans outside the ground despite France's final day of a national Covid-19 lockdown.
Four-time champions Toulouse made sure of their place in the final on Saturday with a 21-9 home win over fellow Top 14 side Bordeaux-Begles.