Flank Siya Kolisi is expected to make his first Test start when the Springboks take on Ireland at Newlands on Saturday, ending a strange, and probably unwanted, record he shares with prop Coenie Oosthuizen.Since 2013 Kolisi has earned 13 Test caps - all as a replacement - something only Oosthuizen has matched, before making his first start for the Boks. The pair will now share that record.Prop Ollie le Roux, who was perhaps the Springboks' most famous substitute, started his first three Tests before enduring an 18-match sequence when he only appeared as a replacement.In his 13 appearances, Kolisi has played a total of 271 minutes of Test rugby, or 21 minutes per game, which is about the norm for a substitute.When the Boks run out against Ireland on Saturday, it will be almost three years to the day since Kolisi made his Test debut against Scotland in Nelspruit, coming on as a replacement for Arno Botha.Botha sustained knee ligament damage early in the game and the 75 minutes Kolisi played that day is the most time he has played for the Boks in a single game.He has twice come on immediately after the halftime break - against Samoa at Loftus Versfeld in 2013 and against the All Blacks at Ellis Park later that year. But generally, his appearances have been limited to a handful of minutes in the final quarter.Kolisi, who turns 25 next week, has had to wait a long time to wear a single digit number on his back in a Test rather than No 19 or 20.It is a sign that new Bok coach Allister Coetzee trusts Kolisi implicitly, after nurturing him at the Stormers over five years.Previous coach Heyneke Meyer never seemed to have the same trust in the Stormers flank, which was never more starkly portrayed than at last year's World Cup.Flank Willem Alberts was a late withdrawal from the Bok starting team to play Japan in the World Cup opener and Kolisi was the only fit flank in the squad at the time. But instead of simply elevating Kolisi to the starting lineup, Meyer turned to lock Pieter-Steph du Toit to play in the No 7 jersey.Kolisi played for 17 minutes off the bench.While Kolisi will be celebrating his first start, others will also enjoy their debuts.Scrumhalf Faf de Klerk, hooker Bongi Mbonambi and possibly lock Gerhard Mostert (if Du Toit fails a late fitness test) should all make their Test debuts.Centre Lionel Mapoe is also likely to be rewarded with a Test start...