Riewoldt, Hayes and Adam Schneider are likely to be called up for the third round of the NAB Cup after modified pre-seasons.
However, Sam Fisher, Rhys Stanley and Sean Dempster will play with restricted game time after missing the first round against Adelaide and Port Adelaide.
St Kilda coach Scott Watters said the Saints would probably have "eight or nine players" from their best side that would miss the hit-out against the Swans.
"There's still a strong development focus," Watters said of the Saints' approach to this weekend.
"You still want to expose players, younger players and some players who are potentially on the fringe, trying to challenge for selection.
"That's a key part of it.
"As you move through the NAB campaign, by the time you get to (rounds) three and four you're getting a lot closer to the side you want on the park."
Riewoldt and Hayes have had modified pre-seasons after knee and heart surgery respectively but have not had any setbacks and are training well.
Schneider is coming off a restricted program because of a foot injury but trained with the main group on Thursday at Seaford.
Justin Koschitzke and Clint Jones worked away from the main group at times while Riewoldt and Hayes weren't sighted.
Watters said he didn't want to put expectations on his team this year with the continuing focus training and improving the younger players.
"What can we achieve? I'm not one who really wants to put limitations or measurements or make predictions," he said.
"I'm certainly not going to tie the club to any predictions, one way or the other at this point.
"We need to focus on our training, our development, make sure out of our senior group we get their absolute best and fast track as many younger players as we can."
Watters also responded to reports that former Saint Jason Gram believed he hadn't done anything that warranted his sacking in October last year
He said he rested "pretty comfortable" with what had been a tough decision to terminate Gram's contract after the ex-Saint's personal issues required involvement by the authorities.
"It's a tough decision on a player I would prefer was still here and that he'd been able to work through some of the challenges he was facing and react to the guidelines that were set in front of him over 16 months," he said.
"I don't want to grandstand on the disappointment of Jason and his position now.
"He gave a lot to this club over a period of time, there's a level of disappointment he's not here but ultimately, the right decision was made for this football club and this team."
Watters said the "right level of support" was offered to Gram, and continues to be now.
He also said St Kilda's recent history with off-field scandals did not encourage the decision, despite Gram's suggestion in a News Limited article the Saints might "have felt the need to jump on me".
He added he would love to see Gram get his life back on track and resume his AFL career after a season playing for North Albury but that he wouldn't fit into the Saints' plans next year.
Nick Riewoldt is a forward in NAB AFL Fantasy. He averaged 85.68 points in 2012. Register your team at our AFL Fantasy Hub.
Jennifer Phelan is a reporter for AFL Media. Follow her on Twitter @AFL_JenPhelan.
