The Republic of Ireland international was stretched off in the first half of Monday's 2-2 draw with Leicester City after colliding with Boubakary Soumare.
Coleman took to social media on Wednesday to allay fears that he had sustained an anterior cruciate ligament injury.
The right-back posted on Instagram: "Just wanted to update you all, thanks so much for all the well wishes. Just back from my scan and pleased to say I have no ACL damage. Be back soon."
Although the injury is not as serious as originally feared, the Everton captain has sustained ligament damage.
Speaking ahead of Monday's home meeting with Brighton & Hove Albion, Dyche told reporters: "It's still going to keep him out.
It's still a ligament injury that needs sorting out, but everyone feared it was his ACL, and it's not."
When asked if Coleman would feature again before the end of the season, the Everton boss replied: "I doubt it. I don't think so."
Coleman has made 394 appearances since joining Everton from Sligo Rovers for £60,000 in 2009, but with his contract set to expire in June, there is a possibility that he has played his last game for the club.
Commenting on Coleman's future, Dyche added: "Like all the players, we are having communication with the relevant people and their agents.
"But Seamus's focus is solely on the club, as you can imagine. Being the servant he is to the club, and the way he is, he hasn't even had one question to me about it.
"We don't want to clutter that with anything other than being respectful and truthful with the players."
With four games left to play, the Toffees are languishing in the relegation zone with one point separating them from safety.