PORT Vale midfielder Chris Birchall has been ruled out for up to six weeks after a knee operation.
The 31-year-old was injured after coming on as a substitute in Monday's 1-0 win at home to Bury.
Manager Rob Page said: "Birchy came on and tweaked his knee within the 10 minutes he was on. We are looking at five to six weeks, hopefully a bit sooner.
"He was frustrated because, straight after the operation, he had his full weight on it and was walking on it. But that seems to be the case when you have a cartilage injury like that."
Birchall has started six games, made six substitute appearances and been a reliable performer after signing a new one-year contract in the summer.
Page added: "It is disappointing for him. He is a great lad to have in and around the changing room and a great lad to be able to start. He has proven he can score goals for me. He's also a great lad to have because I can trust him 100 per cent if I need him to come on at any stage of the game, whether that is defensively or to give us something to change the game.
"So, he will be a miss for us. But it gives somebody now an opportunity to step into his shoes."
Louis Dodds is set to take Birchall's place in the match-day squad against Swindon on Saturday having returned to training after missing two games with a hamstring strain.
Striker Ajay Leitch-Smith hasn't trained this week after he was forced off at half time against Bury having taken a bang on the hip. However, Page is hopeful the centre forward will be fit for Saturday.
Uche Ikpeazu has also resumed training after missing the Bury game through illness.