One of four freshly minted All Blacks, the possibility of hearing his name read out in the national team's first squad of the year this week wasn't on his radar in the slightest.
With his Super Rugby season for the Chiefs limited by concussion, the 22-year-old had his sights set on getting his game legs back at club level in preparation for the Mitre 10 Cup.
After two games for Waikato club Hautapu, the 22-year-old loose forward settled in to watch the All Blacks 39-man squad announcement for the first two games of the Rugby Championship. The last thing he expected was to hear his name read out.
"I thought maybe I needed to play a little bit more but I'm stoked to be included here after maybe not getting as much footy as I would've liked," he said.
In his second season with the Chiefs, Jacobson made just eight appearances. But while his time on the pitch was limited, his production certainly wasn't.
Jacobson was one of the club's most efficient tacklers, averaging 13 per game at a success rate above 92 per cent. He also showed flashes of his deep attacking tool kit, with a host of try assists, line breaks, tackles busts and running metres.
It was enough to catch the eyes of the All Blacks selectors, who were able to give Jacobson an opportunity after Liam Squire made himself unavailable for selection.
"It's a little bit daunting, eh," Jacobson said. "There are a lot of big dogs here, and I'm just walking around like 'hi, I'm Luke'. It's exciting. I'm a little bit nervous, a little bit on edge, but I imagine some of the other boys are too.
"I've dreamed about it since being a five-year-old. It's everything and more. It's going to be awesome to just get out on the field with the other players and coaches and soak up as much as I can."
Jacobson joins the rookie ranks alongside Highlanders No 10 Josh Ioane, and Crusaders backline duo Braydon Ennor and Sevu Reece.
Whether Jacobson will get to make his debut in the first two matches of the Rugby Championship later this month remains to be seen, but with incumbent No 8 Kieran Read likely to stay in New Zealand to recover from this weekend's Super Rugby final, there's every chance Jacobson sees time at the back of the scrum if not in his primary position on the blindside.
When asked about where he sees himself fitting into the All Blacks frame, Jacobson said he had no preference over where he plays and is simply happy to slot in wherever he was told to - if he is given the opportunity.
"I'm easy … Mate, chuck me out there on the wing. I'd love to get out there."