The Irish province beat the French club, their nemesis in the two previous finals, to open the campaign before travelling to northern England, where they can take a big step towards reaching the last 16.
Sale top the English Premiership and began their Champions Cup season with an impressive 28-5 win over Stade Francais in Salford which included a fine performance from England centre Manu Tuilagi.
"You can't take your foot off the throat at all in this competition or you'll get stung," Leinster attack coach Andrew Goodman told reporters this week.
"They're one of the form teams in the Premiership, Manu's back in the mix there and they have some strike power right across the field," the New Zealander added.
La Rochelle, coached by former Ireland fly-half Ronan O'Gara, are licking their wounds from their first Champions Cup defeat since May 2021.
This Saturday, they switch the wet and windy French winter on the Atlantic coast for 24 degrees Celsius (75 degrees Fahreneit) in Cape Town, as they play the Stormers.
South Africa winger Dillyn Leyds left his hometown in the Western Province in 2020, having graduated from the Stormers' academy.
"I know the coaching staff really well. I worked with them since I was 16 years old. They’ve had a big role not just in my life as a rugby player but as a human being as well," Leyds told AFP.
"They're good guys and I often chat to them to see how they're going, exchanging ideas.
"I think I'll keep some of our plans to myself for next weekend," the 31-year-old added. 'Job to do'
Leyds returns to Cape Town on a long weekend with Friday a newly created public holiday to celebrate the Springboks' fourth Rugby World Cup win.
"Cape Town is a good place to be in December, it's summer over there now, heading into the festive season there's lots of parties everywhere but we need to do a job at the end of the day," Leyds said.
"Nothing would make me happier than going back to Cape Town and getting a win over the Stormers and then share a beer with my good mates after the win," he added.
Another highlight of the second round is record five-time winners Toulouse's trip to Harlequins, who are buoyed from Sunday's scintillating 31-28 win at Racing 92.
Scotland full-back Blair Kinghorn is set for his second Toulouse appearance after scoring on his debut last weekend, days after arriving from Edinburgh in a mid-season deal.
"It's been fairly crazy. It's all happened really quickly," Kinghorn told AFP on Monday.
"Trying to get accommodation sorted, your medical, visa.
"All whilst trying to learn the calls, the language, a new set of boys," the 50-time international added.
Racing, meanwhile, travel to Belfast to take on 1999 winners Ulster while Bath, who won it a year earlier in 1998, travel to Cardiff.
Fixtures (all times GMT)
Friday
Pool 3: Bayonne (FRA) v Glasgow (SCO), Northampton (ENG) v Toulon (FRA) (both 2000)
Saturday
Pool 1: Saracens (ENG) v Connacht (IRL) (1300), Bordeaux-Begles (FRA) v Bristol (ENG) (1515), Lyon (FRA) v Bulls (RSA) (1730)
Pool 2: Ulster (IRL) v Racing 92 (FRA), Cardiff (WAL) v Bath (ENG) (both 2000)
Pool 4: Stormers (RSA) v La Rochelle (FRA) (1300), Leinster (IRL) v Sale (ENG) (1730)
Sunday
Pool 2: Harlequins (ENG) v Toulouse (FRA) (1515)
Pool 3: Exeter (ENG) v Munster (IRL) (1300)
Pool 4: Stade Francais (FRA) v Leicester (ENG) (1730)