Keith Hill fears Rochdale forward Jamie Allen's season is over because of a head injury.The Dale forward needed to go to hospital on Tuesday night following a clash with Oldham full-back Mat Sadler in the first half. Allen was one of three players, along with Peter Vincenti and Stephen Dawson, that needed to come off before half-time in a 3-0 derby-day loss which cost Rochdale a place in the top six. Hill now expects Allen to miss the final nine games of the season because the wound may require surgery. "We can't legislate for what happened to Jamie," said Hill after the match. "I don't think he'll play again this season. It's in a serious position, the cut, and it's deep, it's long and he's gone to hospital. It looks to me like it will probably need surgery so his season's probably over. That's just a guestimation. "It was a fully-committed challenge from both players but that's what you get sometimes. It's just unfortunate because Jamie's a special player, but he'll bounce back."