It really depends on the dog, more than the breed.
There is a big difference between a 1 year old high drive WL GSD, and a 2 year old low drive SL.
Some dogs have more of an off switch than others.
Could you work in a nice brisk walk and some play time, followed by time to settle before you leave for work? These would both help.
Any chance you could get home at lunch, or before practice to let the dog out? Any break through the day will help. Maybe a family member that could break the dog?
I would highly suggest crate training, as it will keep your dog, and your stuff, safe while you are gone.
Things to keep the dog busy will help. Buster cube, frozen Kong full of peanut butter... stuff like that.
My dogs do fine at home for 9-10 hours at a time, but they have all their physical and mental needs satisfied through exercise, training and play. One was never crated, because he was 4 when we got him, terrified of his crate, and completely trustworthy in the house. The other was crated for the first year, until he was 3 and more mature.