Coltman (23) has been all energy for the Highlanders so far this season, making an impact when he has come off the bench as a top runner with the ball in hand.
If all the forwards played with his energy levels, the Highlanders would not be winless going into their sixth game.
He is relishing his chance to play at this level, and is backing up an impressive first-class season with Otago last season.
''It is a lot different, but I am loving it. Just the way the game is a lot more physical and a lot quicker. In that way it is completely different from the ITM Cup,'' he said.
But he concedes there is something which is taking up a fair portion of his time.
''I've got to work on my lineout throwing. It is just to get the timing and that right. It is getting there, though,'' Coltman said.
A couple of poor throws near the end of last week's game against the Reds were particularly costly.
Coltman spent much of his early rugby career playing prop, but it was only when he was picked for the New Zealand Colts in 2010 that he had a crack in the No 2 jersey.
That is where his future appears to lie, and throwing the ball in straight and accurately will take time to perfect.
''The coaches are happy with the way I am playing, but for the lineout throwing. But I'm working hard on it.''
So, Coltman is on homework duty for the foreseeable future, but he is not shying away from it.
He will start off the bench tonight and is bound to come on at some stage for captain Andrew Hore, in an attempt to give the Highlanders some energy in the dying stages.
The Taranaki product, who journeyed south to study physical education at the University of Otago, has been picking up plenty of tips from his heavyweight front-row colleagues, Hore and Tony Woodcock, and is sponging up the information.
He has put on about 4kg in the past few months since joining the Highlanders and says that is helping him around the field.
His only previous game at Eden Park is a good memory: Otago's first win at the venue for 35 years, a couple of years ago.
''That was great that night. Just the way the guys hung in there. We just need to do some more of that this week. We're not far away. The guys have been working hard.''
Working hard for Coltman, though, stops short at a trip to the hairdresser.
His wild look stems from a hatred of shaving.
''I think it was about March last year that I last had a shave and got my hair cut. I just can't be bothered really. The girlfriend does not seem to mind. She quite likes it.
''Mum and Dad don't care. Dad reckons he used to have a mop like mine when he was a kid, so he is all right with it.
''I don't think it affects my play at all.''
Coltman is full of energy and thrust, and those qualities need to spread to his forward mates for the Highlanders to succeed tonight.
They have lost the battle on the advantage line in the past couple of games. The Blues have some bruising forwards - the likes of Steven Luatua and Peter Saili - who have to be stopped.
The Highlanders backline has plenty of firepower, but the forward pack needs to muscle up to secure its first win.
Highlanders v Blues
Auckland, tonight, 7.35pm
Highlanders: Ben Smith, Buxton Popoali'i, Jason Emery, Ma'a Nonu, Hosea Gear, Colin Slade, Aaron Smith, Mose Tuiali'i, John Hardie, Jarrad Hoeata, Josh Bekhuis, Brad Thorn, Chris King, Andrew Hore (captain), Jamie Mackintosh. Reserves: Liam Coltman, Ma'afu Fia, TJ Ioane, Elliot Dixon, Fumiaki Tanaka, Lima Sopoaga, Phil Burleigh.
Blues: Charles Piutau, Frank Halai, Rene Ranger, Jackson Willison, George Moala, Chris Noakes, Piri Weepu, Peter Saili, Luke Braid, Steven Luatua, Ali Williams (captain), Culum Retallick, Angus Ta'avao, James Parsons, Tim Perry. Reserves: Keven Mealamu, Ofa Tu'ungafasi, Anthony Boric, Brendon O'Connor, Jamison Gibson-Park, Baden Kerr, Francis Saili.
Referee: Steve Walsh (Australia).
