The Red Devils defeated Championship side Millwall on penalties at the New Den, meaning both sides head into the weekend's fixture on the back of impressive cup upsets away from home.
"People will go into that on a real high now and I think cup runs keep enthusiasm going," said Barker.
"It'll certainly keep people in good sprits but now we have a different agenda over the next few days and that is to prepare for Scunthorpe, who went into extra time as well after 5-5 thriller.
"I am quite pleased about that as it could have been quite detrimental to us otherwise."
The match was Barkers first competitive game as Crawley boss, having quit Bury to replace Sean O'Driscoll.