ST KILDA is building a nice contingent of attacking forwards who can hit the scoreboard, but at the start of the year coach Alan Richardson identified his side was missing the defensive presence every team needs.

So he turned to Mav Weller, 24, a young leader who does not think twice about providing the grunt and energy required. 

Since stepping out of the midfield, Weller has thrived in a defensive-forward role and his efforts against Geelong on Saturday night went a long way to taking the ladder leader's scalp.

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"Mav's got defence (in his blood) even playing as predominantly a defensive mid. It comes reasonably naturally and we wanted that in our front half," Richardson said.

"We wanted his speed, his energy and his power to put on a lot of pressure in the front half." 

Weller told AFL.com.au he had enjoyed the freedom that has been afforded in his new forward role. 

But his focus is not just on his individual game. Weller has taken it upon himself to provide an example to a young forward line that consists of Paddy McCartin, Jade Gresham and Tim Membrey.

"I'm more down there for my leadership and guiding a young group," he said.

"Myself and Josh Bruce are starting to play a fair few games now, so it's about growing the group and getting the team in a position where we can play finals down the track and potentially win a flag."

Richardson described Weller's game against the Cats as "outstanding" and it was hard to argue.

The ex-Sun finished with 19 disposals and six tackles, kicking two important goals in a row in the third term to steady the ship as the Saints responded to Geelong's onslaught.

Richardson said Weller, who spent three seasons at Gold Coast, has continued to grow as a player, adding different attributes to become a more rounded player. 

Weller has now played 80 senior games and is regarded as one of the most impressive young leaders at the Saints. 

"I said to him afterwards that he looks like he's improved his speed. He's a very hard player to tackle because of his speed and his power," Richardson said.

"He's had a very consistent year and I thought he was one of our better performers for the night."