He is still registered as a Morton player and featured earlier in the season when the club was struggling with injuries.
However, the former Gretna, Hamilton and Ayr United striker is happy to let one of the younger players look for cup glory against the Parkhead men, if the fourth-round game beats the weather.
"My name is still in the hat," Grady laughed.
"But seriously, I'm not tempted at all.
"I've had my time playing in these types of games.
"I am hoping there is a player in my dressing room who is going to go out and make a name for himself and we are talking about him rather than myself.
"I am still registered to play.
"I have played a couple of times when we had injuries but I felt I was watering my performance down, too busy thinking about the coaching side of it and forgetting what I was on the pitch to do, which was to play.
"I wasn't doing my team mates any favours.
"So the situation is if the players are fit and I'm not needed, then I won't play."
Grady is confident his side can cause an upset but does not buy in to the popular perception that Celtic's defence is vulnerable.
"If a team works hard enough and tries to be positive then they will always create chances no matter what defence you are playing against," he said.
"Yes, they (Celtic defence) can be exposed like any others.
"There are going to be times when they are caught off guard or there has been good play by the opposition but I don't think they are a bad defence.
"They are international players and they are international players for a reason - they make the right decisions at the right times, most of the time.
"Celtic are playing really well and are a bit like ourselves, creating a lot of chances and not taking enough of them.
"So it could be an entertaining game.
"Hopefully, though, we have a few things up our sleeves."
Morton v Celtic. Click here to bet.