Leam Richardson believes each player has a part to play if Chesterfield are to be successful this season.
Armand Gnanduillet grabbed his first goal this term in the fifth minute of injury time to give the Spireites all three points against Southend on Saturday.
The Ivorian under 21 international has been limited to just two substitute appearances but Richardson said each individual must be ready when called upon.
He said: “If you want to win the league you’re going to need every single player.
“Sometimes the most important people are the ones not playing.
“If their minds are right and the focus is correct when they get on the pitch it can be their night.”
The match looked destined for a draw as the clock approached 90 minutes after Freddy Eastwood had cancelled out Gary Roberts’ opener.
But Gnanduillet’s late header produced a dramatic finish which saw the Spireites end the Shrimpers’ perfect start to the season.
And Richardson hailed the professionalism of the players to keep pressing for the winning goal right up to the final whistle.
“They must be fit, they must show character and they must go until the final whistle. It’s the least we expect from them,” he added.