Forster has impressed during a season-long loan at Carrow Road and has been playing a key role in Norwich's bid for promotion back to the Championship.
But Krul is seen as Newcastle's Number Two, and both are eager to take over from Steve Harper.
Fraser Forster: "I have had a good season here and I've been to a couple of other places on loan as well, but you can never get too much experience.
"Steve Harper at Newcastle has had a fantastic season himself and he will rightfully be No.1 next season and of course you want to challenge and push on through pre-season.
"But personally I want to be out playing rather than sitting on the bench somewhere, so obviously I will have to see what happens over pre-season.
"If I'm not playing there I want to be out playing somewhere else.
"Yes, it could be a big decision, but it could be nice to just get out on loan again and see what happens."
Tim Krul: "There was interest from Holland in the summer, but I turned it down because I believe I have a big future here at Newcastle.
"It is frustating being on the bench, but Steve (Harper) knows all about that."