Sydney Swans coach Paul Roos admits to being surprised with the time it has taken Lewis Roberts-Thomson to recover from a foot injury.

LRT suffered ligament damage in his foot against Melbourne in round 19 last season but played through the pain for the remaining six games which worsened his condition.

He subsequently suffered stress fractures to the foot which left him unable to walk let alone train most days during the finals series.

While the medical staff had him listed to return to training mid-November he is now listed as indefinite though he has just returned to the training track.

"He has just started running so he still needs to do some fitness running (before we assess when he will play)," Roos said on Monday.

"I would say it would be round six or seven before we see him eligible to play seniors with his fitness and form."

The extended time off has frustrated both the player and coach.

"It has surprised the medical staff and it has been a bit of an eye-opener for Lewie so I think he would have handled things a little bit differently in hindsight," Roos lamented.

"It is surprising as when we left after the grand final my expectations were that he would have been back at training on 15 November and he is obviously a long way behind there.

"I think it is the inexperience of a young player and not reading his body correctly.

"He would have gone away during the finals and not felt that he was injured. He would have handled things differently in hindsight but sometimes young players aren’t really aware of what is an injury and what is not, how the body is feeling and how it responds.

"If he had his time over again I think he would do a few things differently."

Roos believes Ted Richards will likely play at centre half-back, as he did several times late last season, and is comfortable with the back six.

"We moved Teddy down there on the weekend so I would say our back half with Leo (Barry), Tadhg (Kennelly) and Teddy, it will be pretty similar to last year without Lewie there," he said.

"You have (Nick) Malceski and (Sean) Dempster playing good footy, so our back six are pretty well set, pending everyone gets through this week."

The Swans play Port Adelaide at 7pm on Friday night at Telstra Stadium and entry is free.