Porzingis (back) is unavailable Monday against the Grizzlies, Brad Townsend of The Dallas Morning News reports.

The 25-year-old was considered questionable for Monday's matchup with Memphis due to tightness in his lower back, and he'll end up missing his first game since Jan. 30. Willie Cauley-Stein could join the starting lineup for Dallas in his absence. Porzingis should be considered questionable for the second half of the back-to-back set Tuesday versus Boston.

More News