WHILE a controversial surgical technique could ensure Nick Malceski returns from what would normally be a season-ending knee injury this weekend after just three months on the sidelines, an old-fashioned stomach bug yesterday meant the Swans defender was unable to endure his toughest test to date.

Malceski had been scheduled to undergo 10 minutes of tackling drills at the end of a light training session on the SCG. But feeling dizzy after a bout of gastro, he left the track early and the Swans' coaching and fitness staff will have to wait until tomorrow to see how the line-breaking defender fares under duress.

Given the radical nature of Malceski's surgery, during which a synthetic fibre was used to repair his damaged anterior cruciate ligament, hearts will be in mouths when he endures his first full-contact session. With some experts having questioned the wisdom of adopting the technique pioneered in Europe, the Swans are well aware they will receive heavy criticism if the 23-year-old goes down again.

However, so successful has Malceski's rehabilitation been since he injured the knee in a pre-season match in Hobart on February 17, and such is his importance to the Swans' prospects, coach Paul Roos does not rule out selecting him for Sunday's match against Essendon at ANZ Stadium.

"I haven't really given that a lot of thought," said Roos. "We'll see how he gets through the work at training on Wednesday and Friday before making any decisions. But the hope was that he would play (either seniors or reserves) if he gets through OK."

Meanwhile, Roos' main task this week is refocusing the minds of the majority of players who had the weekend off ahead of a season-defining stretch of matches against Essendon, Port Adelaide, Richmond, West Coast, St Kilda and Melbourne before the second bye in late June.

"The weekends off is a good thing but you have to make sure they have their minds back focused on footy as soon as you can," Roos said. "We had a light run and they had their meetings this afternoon so hopefully that gets them back into it."

To Roos' obvious relief, the four Sydney players involved in Saturday night's Hall of Fame tribute match — Adam Goodes, Ryan O'Keefe, Brett Kirk and Craig Bolton — all escaped unscathed with defender Bolton having recovered from a slight concussion. Luke Ablett (calf) is also expected to return on Sunday.

While he was a state warrior for Victoria, Saturday night's match did little to rekindle Roos' enthusiasm for representative football with the coach seeing a big distinction between the passion with which the old Victoria-South Australia wars were waged and the Hall of Fame exhibition.

"As a spectacle it was entertaining, there was some really good footy, but it wasn't State of Origin and I don't think it was meant to be," said Roos.

"I think they've said it was a one-off and the players clearly enjoyed being part of it. But given how crowded the footy season's becoming they probably should leave it at that."

The Swans resume against an Essendon team suffering from injuries — Scott Lucas, Alwyn Davey, Mark McVeigh are among the casualties.

Essendon captain Matthew Lloyd said yesterday that the side that had conceded an average of 141 points in its past six games was trying to build for the future. "I think we're letting in 15 to 20 more inside 50s and we're going to be heavily scored against if that's happening."