ESPN’s Adrian Wojnarowski and Michael C. Wright added Saturday that there is still no clear recovery timetable.
Leonard has appeared in just nine games this season because of the quad ailment.
Wojnarowski and Wright also reported this is the second time Leonard has utilized outside medical personnel to rehab in New York this season.
Spurs staff reportedly traveled to New York as well to keep tabs on Leonard’s progress.
He made his 2017-18 debut in December after missing the start of the season, but he has not played since Jan. 13 because of his balky quad.
ESPN’s Lisa Salters reported Leonard was possibly nearing a return to face the New Orleans Pelicans more than two weeks ago; however, that didn’t happen.
Last week, Wojnarowski reported the Spurs held a “tense and emotional” players-only meeting led by veteran point guard Tony Parker.
Leonard’s teammates reportedly implored him to return, but he told them he isn’t yet confident enough in the progress of his rehab.
According to Wright, Spurs veteran Manu Ginobili said March 22 that Leonard “is not coming back.”
After finishing third in the NBA MVP voting last season, Leonard has averaged 16.2 points, 4.7 rebounds, 2.3 assists and 2.0 steals per game in 2017-18.
The two-time All-Star and one time NBA Finals MVP has left a massive hole in San Antonio’s lineup.
The Spurs are fourth in the Western Conference at 44-32, but they hold only a three-game lead over the ninth-placed Los Angeles Clippers.
San Antonio hasn’t missed the playoffs since 1996-97, and it hasn’t lost in the first round since 2014-15.