Striker Ryan Lowe sustained a knee injury and Knill is facing an anxious wait to learn whether the club can afford to sign a player.
Knill said: "We are trying desperately to bring somebody in, but we are working within a price range.
"Also, it's got to be somebody that can come in and play.
"I could easily go and get a young kid with no league experience, but that will not be the greatest for us. We have to be selective but the longer it goes, the worse it's getting."