Forestieri is ineligible following his red card in Saturday’s defeat at in-form Preston North End. The 12-goal striker will serve a one-match ban and is likely to be replaced on the left flank by Everton loanee Aiden McGeady.
Centre-half Lees told The Star: “We will miss Fernando because he’s a great player.
“But there have been people who have not been in the squad lately who are really good. We have got lots of options to fill the hole.”
Forestieri was sent off for two bookable offences. His first caution was for simulation while his second came after he was adjudged to have handled Atdhe Nuhiu’s cross.
Lees refused to blame Forestieri for Wednesday’s first Championship loss of 2016.
“These things happen,” he said. “Fernando is probably more upset than any of us. We win and lose together.
“You can see how Fernando plays that he wears his heart on his sleeve. He’s a very emotional player in terms of his desire to win.
“Everyone could see that he was upset and didn’t mean it.
“We really have to get behind him and it’s important we look after him and get him through this because he’s going to win us games.”
However, Lees was critical of Preston’s players part in Forestieri’s dismissal, accusing them of haranguing the referee.
“I wasn’t really happy with every time a decision was being made, especially with the red card, that three or four Preston players were straight around the ref,” said the stand-in skipper.
“It was happening every decision. I thought it was poor and the referee got influenced with Fernando; every time he went down it was being claimed as a dive.
“Sometimes it can’t be helped (surrounding the officials) if it is something blatant, a really horrendous tackle or a goal-scoring opportunity. People are obviously going to get upset.
“I just thought it was a bit needless on Saturday and that Preston were on at the referee about every decision.”