The reigning premier narrowly defeated Koroit 11.9 (75) to 9.8 (62) in the Good Friday Hampden league season-opening fixture at Friendly Societies' Park, however, a head knock to leader Sam Thompson marred the occasion.

Under new AFL Victoria rules, any player concussed must not play for a minimum of 21 days.

"It was quite an interesting game, we're probably really glad we're leaving with the points but probably disappointed in some ways about how the opposition went about it," Battistello told The Standard.

"We all like to play on the edge but there's playing on the edge and there's going too far. So we'll let the league sort that out, they're trying to clean it up and we want our best players playing footy.

"When you have acts like that it's extremely disappointing and with the concussion rule now, especially we're very conservative, we miss one of our great leaders and players for three weeks.

"So we'll let the league sort that out but as an organisation it's been probably happening for a while within the competition now. (We're) very disappointed."

Koroit coach Chris McLaren noted there was no report or send-off for any of his players and didn't see the incident.

The youthful Saints showed plenty of promise and gave the Roosters an almighty scare when they led by eight points at three-quarter-time.

The Roosters however stood tall and kicked three goals to zero in the final term.

Jed Henderson was named the Roosters' best while small forward Connor Byrne was impressive for Koroit.

Battistello praised Noah Kol, who returned to his junior club after a hiatus from football.

"It was amazing, his fitness is extraordinary and he had some real clutch moments in the last quarter and to be out of footy four years we're just grateful that he's committed to us," he said.

Battistello said the Saints' pressure was strong and his side played good in patches.

He congratulated veteran Saint Dallas Mooney for reaching 250 games.