Coventry City midfielder John Fleck looks as if he will be out of action for about three weeks as he recovers from the hamstring strain he picked up in the 1-1 draw at yeovil on Saturday.
It was his first competitive game for the Sky Blues and he had just sent in a perfect cross for Cody McDonald to head in the opening goal.
Just after the half hour mark, the summer signing from Rangers was replaced by Gary McSheffrey at the spearhead of Thorn's preferred diamond formation.
Fleck suffered a same thigh injury in the pre-season friendly game at Accrington which meant he missed the 1-0 win in the Capital Cup game at Dagenham and the final two pre-season games.
Thorn was quick to point out that the two injuries were not related and that Fleck did not return too quickly.
Thorn told the CT's Alan Poole: “It’s a shame. It wasn’t a case of taking a risk because he had fully recovered from the first one, but I suppose sometimes lightning does strike twice in the same place.”