Kempny was projected to be a key member of Washington's defense next season. The 30-year-old averaged 18:38 per game last year while recording 18 points in 58 contests.
The Capitals have limited cap space, but can now create more by placing Kempny (who carries a $2.5-million cap hit for the next two seasons) on long-term injured reserve.
It what was seemingly a corresponding move, the Caps re-signed fellow left-handed defenseman Brenden Dillon to a four-year deal carrying a $3.9-million cap hit. He joins John Carlson, Dmitry Orlov, and Nick Jensen as the only other Washington D-men signed for next season. Radko Gudas (UFA) and Jonas Siegenthaler (RFA) remain unsigned.