The others, as they seek to avoid a fourth loss to an Australian team this season when they play the Force in Perth, are "scrum", "referee" and "props".
It has been a rough few weeks for the Highlanders as they have slid a little on the Super Rugby Pacific table and found themselves on the wrong side of Australian referees when it comes to set-piece time.
Their scrum has been under immense pressure, particularly in the losses to the Reds and the Brumbies, and the whole team seems to have suffered as a result.
Saula Ma’u was given a particularly torrid time against the Reds, and Ethan de Groot had a frustrating couple of weeks before being rested.
Highlanders coach Jamie Joseph has backed his men to get back on track and suggested they have not had the rub of the green from match officials.
"I think they’ve been on the wrong side of some poor decisions, and that’s led to a lack of confidence sometimes," Joseph said.
"The pressure to get it right is high, internally. We’ve obviously got a very proud history at the Highlanders of having a very good set-piece, and the last two games, you know, getting on the wrong side of the referee, is something we’ve got to rectify."
The Highlanders have had a run of Australian referees controlling their games.
That was more significant than people realised, Joseph said.
"I think they’re a lot more technical than the New Zealand refs.
"They have a tendency to pick up every little bit. We’ve been on the wrong side of a few decisions. I think that’s just part and parcel of the game, and we need to adjust.
"I think that’s the biggest focus for us, really: adapting on the run and adjusting to what the referee’s seeing.
"And it’s just about minimising our errors, really.
"The bulk of our game, we’re pretty satisfied with it. Obviously, a little bit of discipline is letting us down, and just some individual errors.
"The tight games are part of the learning, and then the next part of the learning is closing those matches out."
The end of the Force game will mark the halfway point of the Highlanders’ season.
They will either be 3-4, feeling like they can compete with anyone and thinking another three or four wins in the second half of the campaign can seal a playoff spot, or they will be 2-5, having lost four straight, and wondering where the next win will come from.
Joseph furrowed his brow when asked if he would give the Highlanders a pass mark so far this season.
"That’s a hard to question to answer.
"Lots of things are going to happen from now on. Teams are going to streak ahead, some teams are going to fall away, so it’s important we get a total performance at the weekend and take it from there."
This feels like a game of special significance for the Highlanders.
They are eighth and their opponents sixth, and defeat would leave a worrying gap to the playoff spots.
Some history favours the Highlanders, who have beaten the Force in seven of their past encounters.
Some history makes less pleasant reading: they have lost 11 of their past 12 games in Australia.
Beyond getting the scrum right, they will need to find a way past the staunch Force defence.
Carlo Tizzano (108), Nick Champion de Crespigny (102) and Tom Robertson (96) are the three leading tacklers in Super Rugby.
Highlanders forwards Fabian Holland (95) and Withy (94) are fourth and fifth respectively.
If the Highlanders forwards can hum, there is some serious speed and form in the backs to hope the force may actually be with the visiting side tonight.
Highlanders v Force
HBF Park, Perth
Saturday 9.35pm (NZ time)
Highlanders: Sam Gilbert, Caleb Tangitau, Thomas Umaga-Jensen, Timoci Tavatavanawai (captain), Jona Nareki, Taine Robinson, Nathan Hastie, Sean Withy, Veveni Lasaqa, TK Howden, Mitch Dunshea, Fabian Holland, Saula Ma’u, Soane Vikena, Ethan de Groot.
Reserves: Jack Taylor, Josh Bartlett, Sefo Kautai, Will Stodart, Michael Loft, Adam Lennox, Tanielu Tele’a, Michael Manson.
Force: Mac Grealy, Harry Potter, Sio Tomkinson, Hamish Stewart, Dylan Pietsch, Ben Donaldson, Nic White, Vaiolini Ekuasi, Carlo Tizzano, Nick Champion de Crespigny, Darcy Swain, Jeremy Williams (captain), Tom Robertson, Brandon Paenga-Amosa, Marley Pearce.
Reserves: Nic Dolly, Atu Moli, Josh Smith, Reed Prinsep, Will Harris, Isaak Fines-Leleiwasa, Max Burey, George Poolman.
