Johnson told the City website: "It was a chance for me to get to know the players better and for them to learn a bit more about me.
"We enjoyed terrific facilities for training and had the sun on our backs for a few days which did everyone good.
"There were times to relax, but we also worked hard and had some long and fruitful discussions about the challenges that lie ahead this season.
"The response of the players to all we asked of them has been first class and all in all it was a hugely worthwhile trip."