McDonald noted Spurs head coach Gregg Popovich said the injury isn't as serious as initially thought, but Lee still won't take the floor for the next contest against the Golden State Warriors.
According to Michael C. Wright and Ramona Shelburne of ESPN.com, Lee suffered a partially torn patellar tendon during the first quarter of Saturday's Game 3 loss. He never returned to the contest.
This is yet another blow for a Spurs team that is already facing a daunting challenge against Golden State. The Warriors lead the series 3-0 and are a victory away from their third straight trip to the NBA Finals.
What's more, Spurs star Kawhi Leonard hasn't played since suffering an ankle injury during Game 1, and Tony Parker is out for the remainder of the playoffs with a ruptured quadriceps tendon.
Lee is averaging 4.1 points and 3.8 rebounds per game in 15 postseason contests this year.