Slavisa Jokanovic was made to count the costs of a missing defender and a late Derby equaliser.
The Fulham boss suffered Tomas Kalas limping off in the 2-2 draw with a hamstring strain that will keep the Czech international out for two weeks at least.
Whites came from behind to lead 2-1, but a rearranged defence marked thin air at a 75th minute corner and Alex Pearce headed in to levell.
Fulham also started without a recognised striker. Chris Martin was unavailable to both sides - his parent club and his loan side under the terms of his spell at Craven Cottage.
“We went with Floyd Ayité and Sone Aluko in this area,” Jokanovic said. “Floyd scored the goal, we created many, many chances and we offered the better football.
“My side must be clinical after their mistakes, and this was the situation that we found today in the game. But from another side, I can be satisfied. In my opinion we played very good football.
“When we start being more solid and cut out these mistakes, we are going to be higher in the table, and we’re going to be more competitive.”
Kalas will miss the remainder of 2016.
“It’s a hamstring and at this moment I don’t know exactly what happened with him,” Jokanović revealed.
“Guaranteed it will be two weeks he’ll be out of the squad, but I don’t have more information than that at the moment.”
