Fisher, who PNE sold to Middlesbrough in January for a reported £300,000 fee, suffered a freak knee injury at home during the summer.
Boro manager Neil Warnock said: "We’re not sure at the moment but it doesn’t look very good,”
"I’ll know tomorrow but it’s looking like an operation and you’re talking nine months so we’re not optimistic about that.
"From what he’s telling us it was a complete accident the way that he did it, with a mate slipping and falling on him and crashing onto his knee.
"It’s the back of his knee.”
Here is a round-up of all the news from the Championship, including the latest transfer talk and gossip.
5. Villarreal ready fresh Danjuma bid
La Liga side Villarreal are said to have not given up in their attempts to sign Bournemouth's Arnaut Danjuma, despite seeing a bid close to £13m rejected. (Sport Witness) Photo: Mick Walker
6.
Birmingham City are the latest side to be credited with an interest in Wolves defender Dion Sanderson. They're looking to sign the player on loan. (The Athletic) Photo: Frank Reid
7. Arsenal eye former PNE loan goalkeeper
Arsenal are interested in West Bromwich Albion and England keeper Sam Johnstone who had two loans spell with Preston. (The Athletic) Photo: Press Association
8. Bournemouth agree keeper deal
Bournemouth have agreed to sign Newcastle keeper Freddie Woodman. (Bournemouth Echo) Photo: Bruce Rollinson