Wilson has six goals in the league.
Eddie Howe said that his side are dangerously close to not being able to field a team for their game at the end of the month.
The two forwards suffered injuries during the game at St James' Park.
Wilson could be facing months on the sidelines.
Two points behind 17th-placedWatford,Newcastle are 19th in the table.
Howe said that Callum's injury looks severe. I was afraid for him when he went down. A pull, not a knock.
Two goalkeepers and two teenagers who hadn't started a match were among the eight replacements named by the boss.
He told Sky Sports that they were thin on the ground.
These are difficult times for us. I think it's 13 plus a goalkeeper to have enough players for a game. We're going to be very close to that number.
Wilson went off in the first half with a calf injury and Saint-Maximin pulled up with a hamstring problem after Edinson Cavani had scored an equalizing goal.
"Allan, I think he's serious enough to bring him off."
Widespread injuries, including the suspension of iusca hayden, have left the team without defenders, while they have also played more games than any other team.
Goalkeeper Karl Darlow, defenders Ciaran Clark and Matt Ritchie, and Joe Willock were all missing from the squad.
Wilson has six goals in 19 games, while Saint-Maximin has four in 19 games.
Allan Saint-Maximin went down injured in the second half and there was no one around.
Pat Nevin, a member of the commentary team at the radio station, felt that the players would be missed.
"We don't know how bad the injuries are," said Nevin. "Callum Wilson was having a great game before he pulled up."
He holds the ball up so well, he's not just a goalscorer. If Allan Saint-Maximin is out for more than a week or two, it would be a disaster. The cost to them is immense because they need their best two players.
Eddie Howe needs time to bring in other players.
There are 15 top-flight matches that have been called off this month, including the two games that were scheduled to take place on 28 December.
