Euro landmarks for two Boks
Scrumhalf Pienaar will make his 100th appearance for Ulster after being named in the team to play Kirchner's Leinster in a Pro12 encounter on Friday.
Kirchner will make his 50th Leinster appearance – he will start on the wing.
Both Pienaar and Kirchner represented South Africa at this year's World Cup.
Kirchner, who joined Leinster from the Bulls in 2013, made his first appearance for the Irish team in a 16-13 win over Connacht at the RDS Arena in October 2013.
His first try came just a few weeks later at home against the Scarlets in what was a man of the match performance from the versatile Springbok back.
Kirchner also ran over two tries and set up one for Shane Jennings in the 2014 Pro12 Final against Glasgow Warriors at the RDS.
Pienaar joined Ulster from the South African-based Sharks in 2010 and received praise for his performances for the province in the last few seasons.
Pienaar's great form in the 2011/12 season helped Ulster reach the European Cup Final where they lost 14-42 to a strong Leinster side. He was also instrumental in Ulster's march to the 2013 Pro12 Final where he scored all 18 points for his team in the 18-24 loss again to Leinster.
