With 24 international caps to his name, Jantjes had finally established himself as South Africa's premier full back and had set his sights on gunning down Britain and Ireland's elite in Durban, Pretoria and Johannesburg.
It would have been just reward for the 29-year-old's patience and perseverance and an undoubted high point of an international career that had started so brightly but had seemed in danger of petering out.
After making his international debut at the age of just 21 back in 2001, Jantjes missed out on both the 2003 and 2007 World Cups. The former South African Rugby Young Player of the Year faded from the Springbok scene until after the Boks' most-recent world triumph, with the 2009 Lions tour set to be his first appearance in a truly iconic event.
"When I watched the Lions' arrival, it really hit me," said Jantjes, who was replaced by Frans Steyn for the 2-1 series win.
"I took one or two days to throw my toys. But I got over it and moved on."
The injury that destroyed Jantjes' Lions dream occurred as a result of a collision with All Black cap Liam Messan during the Stormers' Super 14 clash with the Chiefs in May and Jantjes has not played or trained since.
With his one chance of facing the Lions now having passed him by, Jantjes is fully focused on his recovery - something he insists is going better than expected, even if fitness remains a long way off.
"I have not seen the incident again, but I was the star in my own movie that night," Jantjes told Die Burger.
"When they were strapping my leg, my ankle appeared to be lying flat on the ground. It was a rotational break and is quite common among footballers. I drew inspiration from players such as Djibril Cisse and Eduardo.
"Normally you go from two crutches to one before you start walking, but I went straight from two crutches to walking. I started crying after about 10 to 15 steps.
"I don't look too far ahead. Hopefully I can have a good pre-season and steadily get involved with the Stormers. My goal is to get back to 100% and only I will know when I am there. It's going to be a long road back."