St Kilda have their forward line of the future locked up, with Josh Bruce signing a four-year contract extension through to the end of the 2020 AFL season.

With 19-year-old full forward Paddy McCartin having already committed until 2018, the re-signing of Bruce - the Saints' best forward last season - was key.

The 23-year-old kicked 50 goals in a breakthrough 2015 campaign, and ahead of his 50th match for the club against Hawthorn on Sunday, is eying future success with the Saints.

"I'm really excited with the direction the club is heading in and the young group they've got together," he told SEN's Morning Breakfast.

"We've seen the likes of Hawthorn and Geelong before that, the guys stick together and they all come together around the same age group and the same amount of games.

"That's how you build a model for sustained success so that's really exciting."

Bruce moved to St Kilda from GWS at the end of 2013 season, having played 13 matches for the Giants.