Derby County's controversial sacking of Richard Keogh and the subsequent fallout has been a distraction to the team, boss Phillip Cocu has admitted.
The Rams captain, 33, was sacked for his involvement in a crash that saw team-mates Mason Bennett and Tom Lawrence plead guilty to drink-driving.
"Last week I said this has a big impact so we cannot say everything is gone," Cocu said prior to Saturday's match with fierce rivals Nottingham Forest.
"It still has an impact."
Keogh is to appeal against the Championship club's decision and the Professional Footballers' Association (PFA) has said it will "robustly defend" the player.
Cocu said they cannot afford to allow the ongoing situation to affect them when they travel to the City Ground for the second East Midlands derby of the season.
"We have to focus on the games." Cocu added. "We have one more game coming up before the international break and it's a very big one so we need all our focus on that."
The Rams, beaten 3-0 at the City Ground in the Carabao Cup in August, would move to within one point of fifth-placed Forest with a victory in the lunchtime kick-off.
"It's a very big game. I like it. Even in the Cup it was sold out and a great atmosphere," Cocu said.
Cocu, who played for Barcelona against Real Madrid, said he relishes the "extra pressure" of derby games but says they must keep their emotion in check.
"These are the best best games to play in, with a lot at stake," added the Dutchman, whose side are 15th in the table and have only one away league win so far.
"The start of week feels a bit different and I like it. That is what football is about. We cannot deny there are differences in certain games and this is an example.
"But it is important to keep the right balance. Too much emotion can be dangerous. We have to keep focused on how we want to play and stay to a tactical plan and we cannot get carried away, which is easier said than done.
"We are in a good moment. Even when we lost in Hull I was very pleased with how we played. We are on the right track combining attitude and football. I see the team progressing and confidence is good."
The Reds would go level on points with the three teams currently in second place with a win and also have a game in hand on all the sides around them,
Manager Sabri Lamouchi said the win in the League Cup tie at the start of the season is not relevant, but was an "amazing" experience.
"It was totally different; it was a cup game with a different context. But it was amazing," he said.
"I do not need to fire up the players. It is an exciting game for everyone, It will be an emotional game, a tough game, a tactical game against a very difficult opponent, not just because of the rivalry but because both teams are similar. In the emotion some players can go crazy.
"We know how the game is important for the fans. I am sure the atmosphere will be fantastic, but we have to focus on the game for the whole game and our performance."