Craig signed a pre-contract agreement with Hibernian last month and Saints rejected a bid to sell the player in January.
But the former Falkirk midfielder hit two goals last month to show his upcoming summer move has not affected him and Maybury expects his former McDiarmid Park team-mate to be his usual determined self on Monday night.
Maybury said: "I find it a little strange that you can sign a pre-contract in the same league but they are the rules.
"I know, once it was announced, it was a big relief for him and he has scored in most of the games since.
"So it has obviously not affected him. I presume he will play and there won't be an issue.
"He is kind of damned if he does and damned if he doesn't. That's part and parcel of it.
"I'm sure he will do the best he can for St Johnstone, there is no other option.
"Hibs fans will see that he does his best for his team and come the summer he will be a Hibs player and he will do the best for us.
"We have got to be wary of him, he is not afraid to have a shot."
Hibs fans know all about Craig's ability to hit the target as the 26-year-old has scored seven goals against Hibs in the previous three seasons and also found the net against them while playing for Falkirk.
Maybury, who played with Craig for two seasons, added: "He takes plenty of shots, gets in the box, works his socks off. He is a great team player.
"We have probably lacked goals from midfield this season. The wide boys chip in and Gary Deegan scored last weekend, but other than that we probably haven't helped Leigh Griffiths enough.
"He's a great lad off the pitch and will have no problem fitting in.
"I spoke to him not long ago and he is really looking forward to it but he understands that he has got between now and the end of the season to do his best for St Johnstone."
St Johnstone, who are a point behind Hibs in the Scottish Premier League, managed to strengthen their squad last month as well as holding on to Craig with midfielders Michael Doughty, Mehdi Abeid and Gwion Edwards all signing on loan from Barclays Premier League clubs.
St Johnstone manager Steve Lomas said: "We got them in to increase competition and to compete for places in the team and a move to the SPL is good for them as well.
"We have lost a few senior players and the boys were very hungry, very keen to play here.
"The senior players know that if they don't perform then the boys are capable of coming in."