The Magpies are three points above the relegation zone having won just two of their past 15 Premier League matches.
And to make matters worse, Almiron (knee) and Saint-Maximin (groin) have joined Callum Wilson (hamstring) on the sidelines.
A Newcastle club statement read: "Newcastle United forwards Miguel Almiron and Allan Saint-Maximin will be out of action until April after picking up injuries during the Magpies' 1-1 draw with Wolves on Saturday.
"Almiron sustained a knee injury and had to be replaced at half-time, while Saint-Maximin suffered a groin injury in the 63rd minute.
"Both have undergone scans and will continue their rehabilitation with the club's medical team.
"Defender Emil Krafth, who was substituted in the same game, is set to resume training later this week."
The injuries have come at a crucial time for Newcastle, who face three of the bottom five clubs - West Brom, Brighton and Burnley - in their next five games.
Wilson is Newcastle's top scorer with ten goals, while Almiron has found the net five times this season.
Newcastle's next highest scorer is Joelinton with three goals and the Brazilian forward struggled once more against Wolves as he had a goal-bound shot cleared off the line by Romain Saiss.
Miguel Almiron and Allan Saint-Maximin have been ruled out until April through injury in a massive blow to Newcastle's survival hopes.