Dikwena were undone by Milton Karisa's second-half goal at St. Mary's Stadium in Kampala on the weekend, with the return leg taking place in Rustenburg this Saturday.
"Thanks to the Ugandan people for a wonderful atmosphere," Johnson is quoted as saying at the post-match press conference in Uganda.
"It can be a better ground, a lot even. I don’t think the football field is a field for playing this type of competition. For future maybe it will get better. For the support and other things well done to Vipers. They won and we are happy to go home with 1-0. We know back home, we will have a different plan. We will play better football and hopefully we will have a better ref as well.
"I don’t think I fell short on the pitch. I thought the man of the match is the man in yellow. We held the ball, we went forward but when we tried to do something, it stopped. For what it’s worth, I think we had few chances. When we were about to score or take an attempt the whistle went off. We can overcome those things when we are at home."
He added: "When you get to South Africa, be prepared to play on a better pitch and better referee. I thought the refereeing was not good but that’s how football is. You win some and you lose some.”
Stars will next host AmaZulu in the Nedbank Cup last-32 at Moruleng Stadium on Wednesday (19h30).