Most outgoing loan deals at Newcastle last season were completed after August with Chris Hughton keen to check on the progress of his younger players before granting temporary deals.
However, anxious Norwich boss Lambert said today: "I can't leave it much longer, that's for sure. I have been on the phone with Chris virtually since the season ended so we have to wait and see.
"We have to try and keep the options open. You can't just concentrate on one thing because he is not our player, he is Newcastle's player and he is going to be a top goalkeeper.
"It's not as easy as some people think and we just have to wait and see. There is no doubt Fraser is going to be a huge goalkeeper. Newcastle have another goalkeeper there who is in really good form.
"We can't do anything if other teams come in for him.
"There are loads of factors to it, it's not just easy saying we are going to get him and some managers saying he must be coming back to Norwich. There are millions of things that can go wrong and basically he is Newcastle's player."