Stephen McPhail is also struggling with a knock and Gray has to decide who partners Dominic Matteo in the centre of midfield. "It's unfortunate that we have a few injuries at a bad time," admitted Gray. "I feel for Seth because he will be out for a while.
"They are important players and I'll wait and have a think about things before deciding which route to go down."
Gray could pick McPhail, but if he pulls out there is Salomon Olembe, Lucas Radebe and teenager Paul Keegan as contenders for a midfield role while Jamie Winter has also impressed there in the reserves.
Gary Kelly has midfield experience, but Gray has little cover at right back with Frazer Richardson (ankle) ruled out.
"We've still got a massive task," added Gray. "All Saturday's win does is give us an opportunity. We've got to make the most of that opportunity and make progress.
"There's always that tension down at the bottom of the table. If you can control the nerves and don't let the situation get to you then you have a chance. Winning matches helps that.
"Everton will be a tough match, but every one is the same because of the situation we're in. People say Everton are out of trouble, but if we win they are only three ahead of us. That's not a lot at this stage of the season. We'll be going all out to win."