The Wellington Hurricanes outside back dislocated the joint during a Super Rugby victory over the Auckland Blues at Eden Park in March and underwent surgery with an initial diagnosis that he might be back by the end of August.
All Blacks coach Steve Hansen, however, indicated last month that he did not expect the 24-year-old to be available until next year.
"To everyone that's been asking (and I really appreciate the support) looks like I won't be back until Super Rugby next year," Milner-Skudder wrote on his Instagram page on Monday.
"Would have loved to get back out on the paddock this year but it's a bit too early. I look forward to getting stuck into pre-season with the Canes."
Milner-Skudder forced his way into Hansen's All Blacks squad last year after some electric performances in Super Rugby and cemented a spot on the right wing. He scored a try in the 34-17 World Cup final victory over Australia.
(Reporting by Greg Stutchbury in Wellington; Editing by Nick Mulvenney)
