"We think Ben McGlynn would be back and maybe Dan Hannebery, and Lewis Roberts-Thomson will definitely play," Roos said.
The Swans topped the ladder after six rounds, but the Cats took them apart on Sunday, winning their 19th consecutive match at Skilled Stadium.
The Swans were competitive early, but lost by 67 points, 19.12 (126) to 9.5 (59).
Roos said the side was too well led to fall apart on the back of the big defeat.
"Even today there were some positive things to come out of it, but I think there's too much leadership in there to worry too much about today," Roos said after the game.
"We were a fair bit off Geelong, and there's no question about that. We're at round seven now and we've got the Bulldogs next week, so we're at a critical period in our season.
"I think it's good for our players to have a little bit of a view from where we've been over the last five weeks, but it's hard to keep young players up all the time.
"This is where we're at today, we're still a fair way behind Geelong, and you've just got to move on pretty quickly.
"We've got a big month of footy starting with the Bulldogs next week, but we need to play a hell of a lot better to beat the better teams in the competition."
Roos said having both Roberts-Thomson and Craig Bolton out of the backline had hurt the side, but that they would have made no difference to the result.
"Lewie's been playing really really well, and it certainly unsettles you, and although it's going to make a difference in the game, not to that extent.
"He and Heath Grundy have been very very good for us.''
