The Wallabies launch their warm-up to the Tri Nations campaign with a clash against Samoa on 17 July, but Deans has seen three more players ruled out for up to two months each in recent weeks.
The latest members of a worrying looking injury list are Reds' prop James Slipper, Waratahs' hooker Tatafu Polota-Nau and scrum-half Luke Burgess. They join Waratahs No.8 Wycliff Palu and winger Drew Mitchell, as well as Berrick Barnes, on the sidelines.
"We've got a number of players who won't be available for the front end of Tri-Nations, who probably at best will be available for the last fixture," admitted Deans.
"There are likely to be some we'll have to make a call on having observed their training. There isn't a lot of risk in that now because you can't hide in terms of the conditioning work that you do.
"But we won't be picking anyone who hasn't shown that they are close and ready to go. It's such a short campaign, you just can't afford to."
The Wallabies open their World Cup campaign against Italy at Auckland's Eden park two weeks after their end their Tri-Nations fixtures against the All Blacks in Brisbane on 27 August. Ireland is also in the same Pool at the World Cup.
There is at least one piece of good news for Deans in that his inspirational skipper Rocky Elsom is back up and running and looks set to be fit to lead the Wallabies against Samoa.