The club will also wait and see whether a shoulder injury to small forward Hayden Ballantyne will be enough to keep him out of next week's game against Port Adelaide, but are confident he will too will be ready for finals.
Sandilands was subbed out in the first quarter after copping a knock to the head in a marking contest against Melbourne at the MCG on Sunday.
He left the ground with blood coming from his face and suspected concussion – the result of an accidental elbow from the Demons' Jake Spencer – but Lyon said after the game the issue was Sandilands’ cheekbone.
"It doesn't look great, I could not tell you exactly what it is but it looks like a cheekbone and from there we are really confident," Lyon said.
"I have seen Stephen Milne with two fractured cheekbones play the next week… and with us, Michael Barlow so we know you can play with them.
"Potentially he could miss one-two [weeks] but he will certainly be available when the whips are cracking so that is really positive."
Lyon acknowledged it was an interruption to Sandilands preparation for September action (he has played just six games this season) but said provided his cheekbone was as first diagnosed, he could prepare properly to play a part in finals.
"Our first priority is Aaron's health for himself and his family. Once we take care of that and he is ok, we will then put him to work and he will be fine," Lyon said.
Ballantyne hurt his shoulder just minutes before the final siren when he fell over.
Lyon said the goalsneak had wrenched the shoulder and was upset but he was confident he would return in good condition.
"We are really positive and optimistic but again, will he play this week?" Lyon asked.
"Because of the position we are in, you are really able to look after him and get him ready for when the whips are cracking. That is basically where it sits."
Garrick Ibbotson, missing since round 18, is also a chance to return this week against Port Adelaide, however Lyon said that has been the expectation for a couple of weeks now.
The coach said he expected Luke McPharlin, who has not played since round 15, would return in round 23 against St Kilda.
Clancee Pearce, who has missed the past two weeks, will also be back within the next fortnight.
