Johnson insists the squad doesn't need a huge overhaul.
He told the Evening Chronicle: "When you look back on the season, some of the early draws jump out at you. If we could have turned some of them into wins then we would have cruised home.
"Even if we had found another 10% in performances, it would have made a huge difference because we'd have won a lot more points.
"Some of the games we lost and the mistakes we made along the way were really frustrating. That's the story of the season.
"We were close to being very good; that was the most frustrating thing."