South Africa's World Cup-winning head coach Jacques Nienaber "stamped his mark" on Leinster during his first day at training, Scott Penny has said.

The 51-year-old, who led the Springboks to their second World Cup success in a row, took up his new role this week.

"He was out on the pitch and getting stuck in," said flanker Penny of Nienaber's first Leinster involvement.

Nienaber's post has him working alongside head coach Leo Cullen.

"He got here and introduced himself and had chats with lots of people," added 24-year-old Penny.

"Everyone thinks it is really good. He was out on the pitch for the first time and you can already see him stamping his mark.

"He was obviously pretty successful with South Africa and they are obviously a team that puts a lot of pressure on the breakdowns.

"Hopefully we can learn a bit of stuff from him with regards to defensive breakdowns but also learning how they have made their defence so good over the last few years."

Nienaber worked as an assistant coach with South Africa under Rassie Erasmus, winning the 2019 World Cup, before becoming the Springboks head coach in January 2020.

Before that he also served as Erasmus' assistant at Munster from 2016 to 2017, so this is not his first experience of coaching an Irish province.

Asked what trait of the double World Cup-winning South Africa team he was most impressed by, Penny, who captained Leinster in their opening United Rugby Championship game against Glasgow, said it was their physicality in defence.

"They are obviously big demons of men and you can see that physicality helps them in their defence," he said.

"Obviously, having size helps with their line speed and how impressive they are in the contact and at the breakdown - it makes them a real force to be reckoned with.

"Our defensive breakdown has been pretty good, we have had a fair few turnovers and been slowing things down. That is probably the main area that we put a lot of focus on so it is great to have Jacques in to help with that."

Leinster face Connacht in Galway

Second-placed Leinster beat Munster in the United Rugby Championship last weekend and face Connacht in Galway on Saturday before another rematch with Ronan O'Gara's La Rochelle in round one of the European Champions Cup.

"They [Connacht] are going well this season and are unbeaten at home. It will be a big challenge going down there," Penny said.

"They are coming off a big tour of South Africa as well so will be very tight together, those bonds will be there.

"It will be a tough fixture. They have a lot of ex-Leinster players in there so they know our details, so it is important that we get on top of it right from the start."