Chris Millar could miss his second game in a row for Saints.
Manager Tommy Wright reported: “Chris hasn’t trained this week after being forced to pull out of the United game in the warm up after feeling his groin. So he is in the doubtful category.
“And back-up keeper Stevie Banks has a stiff back and we will make a late decision on him.
“We have watched St Mirren and they have picked up four points over the last three games. They have a lot of good young players so we can expect a difficult game.
“We have to improve on recent games and have to make more of our possession. We actually had the lions share at Tannadice and that is unusual. But we didn’t do enough with it.”
New signing James McFadden will be in the Perth squad.
Wright said: “He got 45 minutes against Aberdeen under-20s and he will get up to speed quickly. He is in the squad for the weekend.
“The great thing from talking to him is that he is still highly motivated. Remember he is only 31 amd he wants to continue his career for as long as possible.
“We are delighted to get him and he will provide us with a creative spark.
“We knew Brian Graham was going to miss the United game but we have him back and Adam Morgan is now settled in, scoring against Aberdeen in midweek. So we have three strikers again, providing us with options.”