The five-time All-Star hasn't played since April 26 because of the shoulder, an injury that Posada tried to play through during the first month of the season.
"Sometime in the first two weeks of June would be something we would be hopeful for," Yankees general manager Brian Cashman said Friday. "But is that realistic? I don't know yet."
Posada threw from 120 feet Friday, his longest distance since getting hurt. The 36-year-old, who signed a $52.4 million, four-year contract during the offseason, is batting .302 with one homer and 11 RBIs in 63 at-bats this year.
New York plans to use him in extended spring training games as a designated hitter or a catcher -- but he won't be allowed to throw in games at first.
"It speeds the process up of maybe getting his legs in shape," Yankees manager Joe Girardi said.
If all goes well, Posada would move up to minor league games in a rehabilitation assignment.
"I told him jokingly to be prepared to wear quite a few uniforms, and he's obviously only interested in wearing that Yankee uniform," Cashman said. "But in reality, without a doubt he's going to have to rehab."
Infielder Wilson Betemit, who strained his right hamstring on May 10, started a rehabilitation assigned at Triple-A Scranton-Wilkes-Barre. The Yankees hope to activate him next week.