All three missed Saturday's 2-1 win over Hamilton, Palazuelos with a stomach bug, and Wallace and Glen with respective hip and knee problems.
Csaba Laszlo is confident the latter pair will have recovered in time for the game at St Mirren Park, while Palazuelos says he is almost over his illness.
"I didn't feel well at all on Saturday and there was little else I could do other than go home to rest," he told Hearts News Today.
"I am feeling much better now, although still a little bit tired. Hopefully, I will have my full energy back in the next day or so.
"Obviously, I was disappointed to miss the game but I think I will be okay for this weekend."
Hearts 13/10, St Mirren 2/1, Draw 12/5