MYSTERY surrounds the fitness of Sydney key forward Sam Reid ahead of Sunday's clash with West Coast at Optus Stadium.

Reid was named in the Swans' starting side on Thursday night but he hasn't been spotted in the west with the remainder of the squad, which arrived on Friday.

Three of Sydney's four emergencies in Will Hayward, who was a surprise omission for the season opener, Dan Robinson and Jordan Foote are in Perth.

The 26-year-old failed to train with the Swans at the SCG on Tuesday, instead heading to the pool, but Reid wasn't listed on the official injury list later that afternoon.

His absence against the Eagles would be a big blow for the visitors and leave superstar Lance Franklin as the only tall forward in the team.

Reid bounced back from a nightmare run of lower leg injuries in 2016 to kick 30 goals from 22 games last season, and his athleticism and versatility allows the Swans to use him in defence if required.

If he is confirmed as a late withdrawal from today's match the Swans could opt for a small forward set-up revolving around Franklin, with Hayward, Tom Papley, Kieren Jack and Oliver Florent giving them some speed and tackling pressure at ground level.

That would leave Dean Towers to work as a mobile centre half-forward, with ruckman Callum Sinclair a chance to rest forward at times to help Franklin in the air.

The Swans declined to comment on whether Reid was in Perth when contacted by AFL.com.au on Sunday.