Elton Jantjies has played a massive part in the Lions' recent success, being pivotal in their successful ball-in-hand approach that helped them reach the past two Super Rugby finals.
But he should also take a lot of responsibility for them not getting over that final hurdle in 2016, against the Hurricanes, and against the Crusaders at Ellis Park last year.
Jantjies has been the best flyhalf in South Africa over the past couple of years. There is no question about it. But he has also been one of the most frustrating players to watch, because of his inconsistency and his unique ability to mix the sublime with the absolutely daft.
Unfortunately for the Lions, and indeed the Springboks, the daft has tended to rear its ugly head in some of the big games, with Jantjies failing to take charge from the pivot position.
Unforced errors are the main reason for his struggles, while he seems also unable to adapt to certain situations, such as weather conditions or the state of play in a match. He wants to play a certain way in any situation, and on more than just a few occasions he has burned himself.
Jantjies is a wonderfully attacking player, who takes on the gainline with gusto and has the ability to bring his loose forwards and his outside backs into the game. He feeds off that momentum and platform the Lions' pack has provided him with over the past few years, and has created a lot of magic.
The Lions are right up there in the Super Rugby try-scoring stats over the past few years, and Jantjies should get a lot of the credit for some of the sparkling rugby they have dished up.
But he tends to struggle when things aren't quite going his way or when he needs to adapt his game when conditions don't quite suit his natural instincts. It's like something in his brain shuts down, and it's hard to fathom that such a talented kid can go from superb to mediocre from one game to another.
Jantjies had a nightmare in the third Test against England at a soaking Newlands. He was visibly out of his comfort zone, dropping routine passes and kicking balls straight into touch. But there was that one moment of magic early in the second half when the Boks finally got on the front foot and he played a major role leading up to Jesse Kriel's try.
When things aren't quite going his way, it seems like Jantjies is trying to force things, trying too hard to make things happen on a rugby field. His natural instincts, which have made him one of the top flyhalves in the country, desert him and he ends up making too many mistakes.
So why does Jantjies draw a blank when his teams needs him the most? Why does he go from superb to terrible?
John Mitchell said a few years ago that Jantjies always needed reassurance that he was being backed to do the business. Most sportsmen probably want to hear that from time to time. But at 27 years old, when will the coddling stop? When will Jantjies finally stand up, live up to his true potential and be the man all South Africans hope he can be?
There is no moment like the present.
Over the next three weeks, Jantjies has that chance to prove he can stand up when it matters. He can be the man to take the Lions all the way and win the Super Rugby title.
The Lions certainly need their star man to come of age if they want to get over the final hurdle that has tripped them up in the past two years.
Jantjies is good enough to be the big-game matchwinner for franchise and country, alike, but no arm around the shoulder from a coach is going to give him that reassurance. He needs to realise that himself.
It's time for Elton Jantjies to put on the big boy pants, and the Lions need them to fit comfortably over the next couple of weeks.