HAMSTRING tightness was the reason behind St Kilda withdrawing key forward Paddy McCartin ahead of the club's round one clash against Melbourne at Etihad Stadium on Saturday.

On the official team lists released 90 minutes before the game, the Saints said McCartin had been managed and replaced in the selected side by small forward Jack Lonie.

But the club clarified its position, with footy boss Jamie Cox saying McCartin, the No.1 pick in the 2014 NAB AFL Draft, would be eased into action in a VFL practice match on Sunday.

"Paddy pulled up a little bit tight in his hamstring on Thursday but was cleared to play by medical staff and selected in the round one side," Cox told the club's website.

"We've subsequently decided to withdraw Paddy from this match and we plan to give him a run in the VFL practice match tomorrow, where we can manage the minutes he will play.

"Given it is round one, we weren't prepared to take any risk with Paddy."

At Etihad Stadium, there has been speculation that the 20-year-old was left out due to team balance, however the Saints insist McCartin's absence is due to a legitimate injury.