The rock-solid presence of Carl McHugh in the Pilgrims' engine room was absent against the Magpies, due to an injury sustained last weekend. In stepped Josh Simpson, who partnered Oscar Threlkeld to create an all-action midfield showing that laid the groundworks for Graham Carey's game-winning goal in the 47th minute.
"We'll just assess him tomorrow and Monday," Derek said of McHugh, "and see how he is Tuesday night. He suffered it in the Crawley game.
"I think that Simpson and Threlekld were very good in midfield. They're good players, and that's why they're in the squad.
"He [Simpson] keeps it well and recycles it very well to other players. Oscar Threlkeld's been a very big player for us because he gets about the pitch well, he makes tackles, and he can pass the ball forward as well."
Early on the first half, Kelvin Mellor was forced to withdraw with an injury of his own, but Jordon Forster came off the bench to reprise his role after seeing himself substituted against Yeovil on Tuesday night.
"He's got a dead leg, so we'll just assess things today and tomorrow," said Derek on Kelvin.
"Jordon did really well. In the game previous, [Tahvon] Campbell caused him a wee bit of a problem and he got booked, and after that you have to take him because there's a risk of being sent off.
"He defended his box very well, blocked challenges and he's a big, robust defender."
Forster, Simpson and Threlkeld all contributed to Argyle rarely looking threatened by County in the second half, as the Greens' defensive solidity continues to improve as the remaining Sky Bet League 2 fixtures are ticked off.
"Over the last four games, we've had three clean sheets," said Derek. "We've won two and drawn two as well, and we've looked like winning the four games, which is good."