Thomas Christiansen's men suffered their third consecutive home defeat and their seventh loss in nine league games as the Rams left Elland Road with a 2-1 win after initially going behind to the Whites.
It was Lasogga who broke the deadlock early on, but he arguably became more and more absent as the game went on. And Whelan insisted that Leeds need to see a lot more from the German even if he did get on the scoresheet.
"I want a hard-working striker, I want someone who's going to cause problems. I want someone who's good in the air, someone who's going to run in behind, someone who's going to bring people into play, someone who's very intelligent, someone that's going to score me goals, but someone who's got the heart and that aggression."
Lasogga was not the only player who left Whelan underwhelmed however, as the former striker also criticised Roofe's display in the defeat.
"I expected a bit more from him this evening. I thought he was very quiet. I thought he did the work off the ball but on the ball, it wasn't the normal Roofe that we expect," he would later add.
The particularly frustrating thing for the Leeds fans right now is many of the players who were on show against Derby were key men during their run at the start of the season that hinted that Christiansen's side could be the team to catch this term.
But unfortunately for the Whites, it has not clicked for a number of players recently. And having had a taste of the automatic-promotion places, the pressure is now on the likes of Lasogga, Roofe and every other player who has under-performed over the last few weeks to turn the fortunes around in the near future.