Introducing a female puppy to a household with a unneutered 2 year old working male dog

i have a 2 year old unneutered working spaniel and I plan to bring a young female golden retriever into the household. Will this have a negative effect on our spaniel? eg effect his ability to work, or make him frustrated.

He may try to hump her as time goes on. It's a natural thing to do, and he won't see a problem with it once she hits her teens. You may want to keep an eye on him. Other than that he should be fine.