But he told the club's official website: "The knee is OK. I took a knock and came off against Peterborough because I didn't want to risk anything. I went for a scan and they found a little bit of blood on the knee but that has gone down now."
Pratley, who was approached by Forest during the January transfer window, knows his side are in for a tough battle.
He added: "They are a good side with a good squad and know how to win games. But coming up from League One with them and now challenging for promotion with them we know what Forest are about.
"We'll be going there trying to win like we do in every other game and we owe them for the defeat at our place in December."
Source: Team Talk
Source: Team Talk