But having moved to Queensland from Tasmania when he was 15, he hasn't spent enough time living in the state to qualify as a priority academy selection for the Suns - something rival clubs can be pleased about.
Weller, the younger brother of former Sun and current Saints midfielder Maverick, sits among the top handful of midfielders available in this year's draft pool.
He has gone through all the talent programs to this point: he captained the AIS-AFL Academy in level one and was a member of the team's leadership group this year, and played well last season for Queensland at the NAB AFL Under-18 Championships.
Weller's 2014 campaign was up and down, but he did average 20 disposals for Southport's senior side this season and understands what the next step will require.
If clubs weren't already convinced of his quality, Weller underlined it with a stellar performance for the Allies in the NAB AFL All Stars curtain-raiser on Grand Final morning.
He gathered 20 disposals and made good decisions with the ball, and showed his skill with two excellent goals, particularly a long, spearing bomb from outside 50.
The 18-year-old's traits are obvious: he uses the ball nicely, thinks quickly, marks well above his head and athletically is very good (he has tested 2.92 in the 20-metre sprint). Weller can be used off the wing but also in the middle, and is best at setting up the play with his efficient disposal.
Weller does everything professionally – his skinfolds were the third lowest recorded at the national combine – and he knows the environment at elite level after his time with the Suns.
At 181cm, Weller isn't a big and strong midfielder. That's reflected in his style, which at this stage is more as an outside midfielder than one who thrives on winning his own ball.
He can do it, and one in three of his possessions in the TAC Cup were contested, but the balance can be improved. He had an inconsistent season, but has jumped around a few different teams.
Click here to check out Lachie Weller's draft profile and watch his 2014 highlights
With his dash, delivery and dare, Weller shares some traits with David Zaharakis. Weller likes kicking goals and has spent much of his season working on using his pace more in games. He is at his best when he arches his back and looks for gaps to break through.
Weller has some admirers inside the top-10 and it wouldn't be a surprise to see him selected there. If not, he won't last much longer.
Weller brings some class and composure to the top end of the draft and he's a player you want to carry and run with the ball. The best thing about him is he doesn't need big numbers of possessions to hurt; most of his touches are damaging.