“In a game of small margins, when the 12th man is behind you from the start, the players value that. It gives them that little bit of extra confidence.
“We are at home, so we want to take the game to Derry City and give it a right go. The fans can help us do that.”
After an excellent 0-0 draw away to title-chasing Cork City last Friday, Bohs almost undid all that hard work as they went 2-0 down to Sligo Rovers in the first half on Monday.
Long said: “We were really good value for the point down in Cork. We kept the ball well and defended well.
“But you couldn’t have had a more contrasting performance to that than in the first half against Sligo. We had tired bodies playing two games in quick succession.
“You can sometimes forget we’re part-time and don’t have the luxury of recovery times between games that some teams do – Derry will be our third game in eight days.
“That said, we know we didn’t defend well in the first half. Sligo caused us problems but they were problems of our own making.
“But we showed great character to fight back – Izzy Akinade got a crucial goal just before half-time and our second-half performance deserved the two late goals to win it in the end.
“It was a great result. Sligo were unbeaten in nine games before that so the lads deserve a bit of credit for turning it around.”
Friday’s opposition Derry have frustrated Bohs in the sides’ two league meetings this season, winning 1-0 on both occasions, most recently at Dalymount Park last month.
Long added: “We were unlucky in the game in the Brandywell but when they came down here we didn’t do enough to win the game.
“There wasn’t all that much between the teams but they’re an organised team and we have to be a bit smarter.
“If we perform like we did against Cork City and in the second half against Sligo, we can progress against Derry.”
Shane Supple and Marco Chindea are cup-tied having represented Crumlin United and Athlone Town respectively earlier in the competition.
Supple, however, is recovering well from an ankle injury he sustained against Cork City last week, which ruled him out of Monday’s game against Sligo Rovers.