Two St Kilda rookies are set to fight it out to become St Kilda’s No. 1 ruckman in the final three games of the season, with Tom Hickey expected to be sidelined with a hamstring injury.

Hickey was restricted severely after incurring damage to his left hamstring during the second quarter in Saturday night’s loss to the Western Bulldogs.

Despite playing a small part in the second half to help the Saints avoid having two players out of the match, the key tall was unable to venture far from the forward 50.

Scans today confirmed Hickey will likely miss the final three weeks of the season, leaving Rowan Marshall and Lewis Pierce to fight it out for a place in the senior side.

Nicknamed ‘The Prospect’ by his teammates, the 201cm Marshall has played a variety of positions for the Saints this year, including taking on Sam Jacobs as the stand-alone ruckman in Round 3.

He was one of the standouts against Carlton in Round 17 playing as a key forward but was originally selected by the Saints as a ruckman.

With Billy Longer sidelined with an ankle injury, forgotten big-man Lewis Pearce could also come in for his second game of AFL footy.

Pierce has become one of the VFL’s leading ruckman while playing for Frankston this season and could add to the one game he played in 2016.

In-form ruckman Tom Bellchambers is waiting for either Marshall or Pierce in what looms as a crucial match-up with the Bombers big man.