Two Chelsea players were shown red cards in the FA Cup third round replay against Norwich.
Pedro and Alvaro Morata were both sent off in that game and will now be absent for the Blues game against Brighton on Saturday.
With his main striker unable to play the game, Conte has admitted he will change the plans he already had for the game.
The Chelsea boss said: “For sure, this is another problem. In this part of the season, at this moment, it’s a big problem. Also because Morata didn’t play against Norwich, or only 20 minutes. He was resting for the game against Brighton.
“For this reason, I have to change the plan. You ask me if I have a plan for this busy period, and you have to have one, but anything can happen – a red card, an injury – and you have to change the plan. For sure, I have to change the plan for Brighton.”
Speaking about what he learnt from the reverse leg against Brighton at Stamford Bridge where Chelsea won 2-0, Conte said: “I learned we have to pay great attention tomorrow. Brighton played a really good game against us, especially in the first half. They were very compact and solid defensively.
“They’re a good team with a really good coach. I had the opportunity to know this coach, and he’s a really good coach. We must pay great attention tomorrow.
“Also because we are playing a game in only two days at 12.30, and many players played 120 minutes, and also the penalties (on Wednesday). We have to pay great attention, we must be focused. Tomorrow the game won’t be easy for us, and we must be ready.”