The Magpies have two training sessions to complete before the match and coach Mick Malthouse said they would determine whether the dynamic forward had fully recovered from his ankle injury.
"I can't guarantee he will (play); I can't guarantee he won't," Malthouse said.
"You can't really test it until you get on the ground. He's been on the ground now for over a week and all indicators are that things are okay, but you just never know sometimes how they will pull up.
"There's a lot of water to flow under the bridge with, perhaps, some guesswork taken out after we conclude."
Medhurst has not played since injuring his ankle against North Melbourne in round six and Malthouse admitted he had been surprised by the length of his stay on the sidelines.
Fellow inclusion Travis Cloke is a lot further advanced in his recovery from a hamstring injury, with Malthouse revealing he may have been able to play last week, but the club decided to err on the side of caution.
"He hurt his hamstring as we all know, but the way it happened in a marking motion with two or three players coming over the back of him, it stretched his leg right out," he said.
"It wasn't the major muscle …all I know is we're been fairly secure with him in the last two weeks. He's been doing a lot of work."
Anthony Rocca remains sidelined with a groin strain despite training well according to Malthouse, but the coach is determined to give the veteran forward the best opportunity to succeed once he does return.
"We're not going to rush him – we've got no need to. It's in the interests of a 31-year-old that you get it right," he said.
"He's going to be judged by a lot of people – fairly and unfairly – and we know what sort of player Anthony is. He's dynamic, he's a player that wants to do everything for the team and when he can't do that he gets murdered and we're not going to see that happen."
Despite Melbourne's position at the tail of the AFL ladder, Malthouse said the clash would be an excellent indicator or how his side was travelling, and labelled the Demons' side as the best they had put on the park this year.
"This will be a hell of a fight, this will be a great test for us," he said.
"The last two weeks (for us) have been good, but this is more than just a Queen's Birthday game for us. The relevance of the day is irrelevant – it's the fact that we're playing Melbourne and we need to keep winning."
