With Freddie Sears missing and Victor Moses struggling, Warnock opted for a 4-4-2 formation against the Rams with Scannell partnering Alan Lee up front. And the Eagles boss was rewarded with a solid performance and a 1-0 win.
Warnock said: "I thought Scannell did well and took his chance.
"He can still be a little stronger and believe in himself a bit more. You know what you're going to get with him, he gave 100%.
"I wanted to play two up front because I didn't want the crowd to get frustrated. I thought 'let's play two up and have a go at them'. I didn't want to play Alan Lee on his own up there."