But Evans told BBC Sussex: "I think Bruce Winfield tells us privately that it doesn't have to come in one season.
"It's our first crack at it. We live in the real world, there's probably seven challengers for the title."
He added: "There's a whole lot of factors that go in to whether you are promoted or not. This is a sustainable plan."
But Evans accepted that after two spells in administration, the club's supporters deserve a team who will be challenging for promotion to the Football League.
"The supporters were here before we were and they'll be here long after we are gone. They're here for life," he said.
"This summer they must have woken up and thought they are in the middle of a dream. That dream is centred around one man in Bruce Winfield, who has put a huge amount of money into the football club.
"Outside the Premier League and half a dozen Championship clubs we are the most secure club in the country."
Crawley start their campaign at home to Grimsby Town on Saturday.
Source: BBC Sport
Source: BBC Sport