Grant sat out the weekend's thrilling victory over Port Adelaide due to disciplinary reasons but could return for Friday night's clash with Collingwood at Telstra Dome.
"I'm assuming [he'll play], but you'll have to ask Dean (Laidley) that one," Simpson said.
Grant and chief of football Donald McDonald spoke with the media at Arden Street on Tuesday, confirming the 293-game veteran had acted against the players' code of conduct.
However, Simpson was unmoved by the events of the last week, noting that the Roos had focused on their match against the Power and will follow that course for the Magpies.
"It hasn't been a distraction for the players or the coaching staff," he said. "The media's probably run with it a little bit and what we hoped would have gone away last week hasn't, so now we've knocked it on the head and [can] get on with it.
"There wasn't really much to report, to be honest. The incident wasn't that big. It was a combination of one or two years of events and we thought it was done and dusted.
"Hopefully it is now."
The ninth-placed Roos meet fifth-placed Collingwood in a clash befitting of a national audience, and Simpson hopes supporters turn out in force.
And he's sure the Grant issue will have no bearing in the lead-up.
"We've always had issues every now and then at the footy club, but ... one thing that we do is we concentrate on what we've got control over," he said.
"It is a big game this week -- Friday night, we only get two a year.
"[It's] Collingwood. We want a big crowd [and] it's our home game so hopefully we get 50,000."
