The Blues are currently in Ireland where they play Forest Green Rovers on Tuesday evening, and Clark was full of praise for both the facilities of Fota Island and how his charges have gone about their business in the early days of summer.
After an arduous Championship campaign which culminated with a dramatic last-day escape from relegation, Clark is eager to see his team prosper to avoid a similar fate next term.
And the former Newcastle United man believes that a good pre-season is key to flourishing when the serious business gets underway next month.
Speaking to the Birmingham Mail in Ireland, Clark said: “The facilities were top class, like we thought they would be, and the lads worked unbelievably hard, the whole group, the intensity was very high.
“They are pushing each other and we had a tremendous week in terms of training, while the game was of a good tempo for us. So we’ve been absolutely delighted.
“What’s also been a positive is that the new lads all seem to have integrated into the group very, very quickly. They’ve settled really well. We look like we’ve got a good team spirit.”
Clark also explained how he is looking to adopt a high-tempo approach to his side's play next season.
“When you talk about style and philosophy of football, you want winning football, first and foremost,” added the manager. “That’s what it’s all about. I want to see wins and I want to see it done in a productive way.
“Certainly I always talk about high-tempo football – and that’s something we’re looking towards. Without the ball a high-tempo pressing game; with the ball high tempo too, which means you have to be working extremely hard for the man on the ball to give him options."
Birmingham begin their Championship campaign with a trip to Middlesbrough on August 9.