Six years ago Trimble scored a try in Ireland's thumping 32-15 win at Lansdowne Road and having missed out when his country have faced South Africa since, he's relishing the chance to lock horns with the Springboks - and Pienaar - again.
"That day was one of my first caps. It was my second season with Ireland," Trimble told the Irish Independent.
"It felt like was starting to impose myself and it was a performance that made me feel as if I deserved to be there. It gave me a lot of confidence.
"Chatting to Ruan Pienaar this week I told him I found a picture of me handing him off in the face. He didn't enjoy it as much as I did! But I definitely have fond memories of these guys.
"He's just chilled out, the most relaxed man I've ever met. He does the right thing 99 per cent of the time.
"He's very composed. You don't often get the same panicking or giving out to boys - that's what you want from your scrum-half. He performs very well under pressure and does the right thing more often than not.
"And I think that's something we have got to do. We'll be doing well to get him flustered, but that's what we've got to do, to put their decision-makers under a lot of pressure, put them on the back foot and slow down their ball.
"At that stage then we have to ask big questions and see if he's as calm under the pressure we'll put him under."
63x46.png){kind=logo}