McCormick, back for a second spell with the club, returned to the starting line-up in the 3-1 win over Cheltenham on Saturday after former Barnet shot-stopper Cole kept goal against Fleetwood.
It means Sheridan has handed two starts to each of his keepers in their four games so far.
"They are evenly matched and there is nothing between the pair of them - I'm very comfortable with either," he said.
"Jake just got the nod (against Fleetwood) because of his performance at Birmingham, he deserved his place for that.
"But I'd made it clear to Luke - keep on your toes and be sharp because you don't know when your time will come and you'll be back in the side."