"We had three weeks of extra training before Christmas, and operations all got done earlier," Roos said.
"I don't think we are going to be behind this year, whereas in the past we've had to try and catch up over this period, we are certainly a long way ahead."
In addition, Roos said that the older Swans senior players still had plenty to offer.
"Hally had an operation, he's looking really good. Kirky had a great year last year and Leo was leading our best and fairest just prior to him getting a hamstring injury."