Johnson told bcfc.co.uk: “It's important we look after him, nurture him and ensure he improves and grows.
"If he produces and does get better and we enable him to make that step up then it will certainly be noticed in football.
"If that happens, who knows who we might be taking on loan next season? We're trying to set ourselves up for the next Tammy Abraham."
The City boss admits it's highly unlikely Abraham would ever come to Ashton Gate permanently, but joked he'd start a whip round if it were possible.
He didn't rule out a potential second season on loan, but added: “It's still early days in his loan really and we should see it for what it is. He's a bright, young player who has really hit the ground running.
“Who knows how things will pan out? Chelsea could go and sign five strikers in front of him or they could hand him a new deal and make him captain! Anything could happen in football."
Abraham has also earned an England U21 call today.