Midfielder Gwion Edwards has also returned to parent club Swansea while left-back Brian Easton (hamstring) and forward Steven MacLean (knee) miss the Scottish Premiership clash through persisting injuries.
And striker Rory Fallon may also wave goodbye to the McDiarmid faithful following the match after Wright informed him he was free to find a new club.
St Johnstone return to Perth having lost 4-0 at Motherwell ahead of last weekend's single-goal defeat away to Ross County.
While they have won just once on the road in the league this season, Saints can boast six home victories out of 10 games and defender Frazer Wright believes the Fair City outfit are a different proposition entirely in front of their own fans.
"We're back at home and our form there has been good," he said. "It's the away form which has been disappointing this season, so hopefully we will get back to winning ways.
"But St Mirren had a difficult time of it too against Celtic at the weekend. It's hard against a side of Celtic's quality but we can't worry about how they will respond to a 4-0 defeat, we just have to focus on ourselves.
"It's a home game, we do well at our own place and we aim to take the points."
St Mirren midfielder Kenny McLean will miss Saturday's game after a troublesome knee injury forced him under the surgeon's knife on Friday afternoon.
Buddies boss Danny Lennon will also be unable to call on midfielder John McGinn for the McDiarmid trip as he serves out a one-match ban, but skipper Jim Goodwin returns following his two-game suspension for elbowing Dundee United's Stuart Armstrong on Boxing Day.
Midfielder Paul McGowan is also in the squad after he was spared jail despite carrying out an alcohol-fuelled assault on two police officers.
"It's a big weight off his shoulders," said Lennon. "Anything like that hanging over you, regardless what you do, is going to have a bearing on you.
"I'm delighted [with the outcome]. He's a loveable wee guy is Paul and I'm delighted this is all behind him.
"We will help him in his recovery and he knows he has done wrong. The most important thing is that we help him along with his correction and that Paul gives a little back to the community for the right reasons. He needs to become a role model that youngsters will look up to.
"We have all made mistakes in our lives but we are one big family here at this club and like any family, if someone is in trouble, you stick by them."
- Sports & Recreation
- Frazer Wright