The Frenchman was injured in the 4-0 win over Hull City at Goodison Park yesterday and immediately went down the tunnel for treatment. He will require a scan on his calf over the next 24 hours.
“We need to make a scan tomorrow, it’s his calf,” Koeman said after the game.
“I’m a little bit worried he might be out for several weeks but we need to wait until tomorrow.”
Schneiderlin took to social media to express his disappointment at his injury but reassured fans that he will do everything he can to make it back as soon as possible.
“I will know more about my injury on Monday,” he tweeted.
“But be sure i will do everything to come back ASAP.”